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Updated: 7 hours 10 min ago

There Was a Doomed Comet Near the Sun During the Eclipse

8 hours 14 min ago

A surprise appearance of a new comet made the April 8th total solar eclipse all the more memorable.

Any dedicated ‘umbraphile’ will tell you: no two eclipses are exactly the same. Weather, solar activity, and the just plain expeditionary nature of reaching and standing in the shadow of the Moon for those brief moments during totality assures a unique experience, every time out. The same can be said for catching a brief glimpse of what’s going on near the Sun, from prominences and the pearly white corona to the configuration of bright planets… and just maybe, a new comet.

The Discovery

While many planned to try and spy periodic Comet 12P Pons-Brooks during totality, astronomer Karl Battams at the U.S. Naval Observatory alerted us to another possibility. A new sungrazing comet, spotted just hours prior. The Kreutz family comet was seen by Worachate Boonplod in the field of view of the joint NASA/ESA Solar Heliospheric Observatory’s (SOHO) LASCO C3 and C2 imagers. These are equipped with Sun-covering coronagraphs that allow it to see the near solar environment. The mission was launched over a quarter of a century ago in 1995. SOHO was deployed to the sunward L1 Earth-Sun Lagrange point nearly a million miles distant. SOHO has since proven itself to be a crucial workhorse in solar heliophysics.

Doomed SOHO-5008 (lower left). Credit: NASA/ESA/SOHO

The comet soon received the formal designation of SOHO-5008. That’s right: SOHO has led to the discovery of over 5,000 comets in its career. Most of these discoveries were thanks to the efforts of dedicated online sleuths, scouring recent LASCO images.

At the time, the doom’d comet was a faint object, located only a few degrees from the Sun. The icy interloper was a tough target to nab during the fleeting minutes of totality, but at least two dedicated astrophotographers managed to catch it. Lin Zixuan saw it imaging from northern New Hampshire. Petr Horálek from the Institute of Physics in Opava Czechia (Czech Republic) was imaging from Mexico as he caught the object.

Like so many other sungrazers, the comet met its demise shortly after discovery (less than 12 hours, in fact), like a sundiving spaceship at a Disaster Area concert right out of Douglas Adam’s Hitchhiker’s Guide to the Galaxy.

A Brief History of Sungrazers

This sort of SOHO versus comet, versus eclipse discovery has only occurred twice: once in 2008 and again in 2020). SOHO wasn’t designed per se to find comets, but its prolific nature as a comet hunter has become an essential part of the legacy of the mission. SOHO has defined whole new families of Kreutz, Marsden and Kracht sungrazing comets. And to think, prior to the mission, only sixteen sungrazing comets were even known of.

One similar case was the Great Comet of 1948, which was also discovered by stunned observers during a total solar eclipse. Another was C/1965 Ikeya-Seki, which went on to become one of the truly great comets of the 20th century. More recently, C/2011 W3 Lovejoy surprised everyone by surviving its perihelion passage 140,000 kilometers from the surface of the Sun. Just one year later, however, 2012 S1 ISON didn’t.

It was a thrilling celestial spectacle, with an added treat.

The post There Was a Doomed Comet Near the Sun During the Eclipse appeared first on Universe Today.

Categories: Astronomy

The Ingenuity Team Downloads the Final Data from the Mars Helicopter. The Mission is Over

Sun, 04/21/2024 - 7:38pm

I really can’t believe that the Ingenuity helicopter on Mars took its maiden voyage in April 2021. On the 16th April 2024, engineers at NASA have received the final batch of data from the craft which marks the final task of the team. Ingenuity’s work is not over though as it will remain on the surface collecting data. For the engineers at NASA, they have their sights set on Dragonfly, a new helicopter destined for Titan.

When Ingenuity took off on its maiden voyage it became the first powered craft to achieve flight on an alien world. It has completed 128.8 minutes of flight covering 17 kilometres. It has extra large rotor blades to achieve lift in the thin martian atmosphere and has performed excellently providing guidance and targets for the Perseverance Rover to study close up. 

Ingenuity helicopter

It’s surprising to think that Ingenuity was only ever designed to be a short-lived demonstration mission. Over a period of 30 days, Ingenuity was to perform five experimental test flights and operate over three years. Unfortunately a rather hard landing damaged its rotor blades rendering it unable to fly again. It’s now sat at Airfield Chi in the now named “Valinor Hills” area of Mars. The team gave the region the nickname as a homage to the final residence of the immortals in Lord of the Rings. 

With Ingenuity now unable to fly the team had sent a software update to direct it to continue to collect data even if the Rover is unavailable. This will mean that it will wake each morning, test the (non-flight) systems are operational, take a colour image of the surface and record the temperature. The team believe such long term data could help to inform martian weather studies and help future explorers. This is a long term purpose for Ingenuity and it has the capability to store data for 20 years! If system or battery failure occurs the data will still be securely stored. The only way to retrieve the data though, will be through another autonomous craft or a human visitor of the future. 

The success of Ingenuity paved the way for a new era of planetary exploration. Next up is Dragonfly, a mission to Saturn’s moon Titan. Costing a total of $3.35 billion across its entire lifecycle it will become the fourth mission in NASA’s New Frontiers Program. The probe will be managed by the Marshall Space Flight Centre but behind them is an international team from many different organisations including but not limited to Goddard Space Flight Centre in Maryland; Penn State University in State College, Pennsylvania; Centre National d’Etudes Spatiales in Paris; the German Aerospace Centre in Cologne, Germany; and JAXA (Japan Aerospace Exploration Agency) in Tokyo.

Artist’s concept of Dragonfly soaring over the dunes of Saturn’s moon Titan. Credit: NASA/Johns Hopkins APL/Steve Gribben

Dragonfly is slated to arrive in 2034. It’s mission will be to visit multiple locations, sampling the minerals to search for prebiotic chemical processes. It will also look for chemical signatures that indicate water-based and/or hydrocarbon-based life. Unlike Ingenuity, its rotors are similar size to those you would find on a drone on Earth. The atmosphere is thick and so there is no need for super-sized blades. 

Source : NASA’s Ingenuity Mars Helicopter Team Says Goodbye … for Now and NASA’s Dragonfly Rotorcraft Mission to Saturn’s Moon Titan Confirmed

The post The Ingenuity Team Downloads the Final Data from the Mars Helicopter. The Mission is Over appeared first on Universe Today.

Categories: Astronomy

Juno Reveals a Giant Lava Lake on Io

Sat, 04/20/2024 - 12:57pm

NASA’s Juno spacecraft came within 1,500 km (930 miles) of the surface of Jupiter’s moon Io in two recent flybys. That’s close enough to reveal new details on the surface of this moon, the most volcanic object in the Solar System. Not only did Juno capture volcanic activity, but scientists were also able to create a visual animation from the data that shows what Io’s 200-km-long lava lake Loki Patera would look like if you could get even closer. There are islands at the center of a magma lake rimmed with hot lava. The lake’s surface is smooth as glass, like obsidian.

“Io is simply littered with volcanoes, and we caught a few of them in action,” said Juno principal investigator Scott Bolton during a news conference at the European Geophysical Union General Assembly in Vienna, Austria. “There is amazing detail showing these crazy islands embedded in the middle of a potentially magma lake rimmed with hot lava. The specular reflection our instruments recorded of the lake suggests parts of Io’s surface are as smooth as glass, reminiscent of volcanically created obsidian glass on Earth.”

This animation is an artist’s concept of Loki Patera, a lava lake on Jupiter’s moon Io, made using data from the JunoCam imager aboard NASA’s Juno spacecraft. With multiple islands in its interior, Loki is a depression filled with magma and rimmed with molten lava. Credit: NASA/JPL-Caltech/SwRI/MSSS

Just imagine if you could stand by the shores of this lake – which would be a stunning view in itself. But then, you could look up and see the giant Jupiter looming in the skies above you.

Juno made the two close flybys of Io in December 2023 and February 2024. Images from Juno’s JunoCam included the first close-up images of the moon’s northern latitudes. Undoubtedly, Io looks like a pizza – which has been the conclusion since our first views of this moon, when Voyager 1 flew through the Jupiter system in March 1979. The mottled and colorful surface comes from the volcanic activity, with hundreds of vents and calderas on the surface that create a variety of features. Volcanic plumes and lava flows across the surface show up in all sorts of colors, from red and yellow to orange and black. Some of the lava “rivers” stretch for hundreds of kilometers.

Io’s sub-Jovian hemisphere is revealed in detail for the first time since Voyager 1 flew through the Jupiter system in March 1979, during the Juno spacecraft’s 58th perijove, or close pass, on February 3, 2024. This image shows Io’s nightside illuminated by sunlight reflected off Jupiter’s cloud tops. Several surface changes are visible include a reshaping of the compound flow field at Kanehekili (center left) and a new lava flow to the east of Kanehekili. This image has a pixel scale of 1.6 km/pixel. Credit : NASA/SwRI/JPL/MSSS/Jason Perry.

Juno scientists were also able to re-create a spectacular feature on Io, a spired mountain that has been nicknamed “The Steeple.” This feature is between 5 and 7 kilometers (3-4.3 miles) in height. It’s hard to comprehend the type of volcanic activity that could have created such a stunning landform.

Created using data collected by the JunoCam imager aboard NASA’s Juno during flybys in December 2023 and February 2024, this animation is an artist’s concept of a feature on the Jovian moon Io that the mission science team nicknamed “Steeple Mountain.” Credit: NASA/JPL-Caltech/SwRI/MSSS

Speaking of volcanic activity, two recent papers have come to a jaw-dropping conclusion about Io: this moon has been erupting since the dawn of the Solar System.

All the volcanic on Io is activity is driven by tidal heating. Io is in an orbital resonance with two other large moons of Jupiter, Europa and Ganymede.

“Every time Ganymede orbits Jupiter once, Europa orbits twice, and Io orbits four times,” explained the authors of a paper published in the Journal of Geophysical Research: Planets, led by Ery Hughes of GNS Science in New Zealand. “This situation causes tidal heating in Io (like how the Moon causes ocean tides on Earth), which causes the volcanism.”

However, scientists haven’t known how long this resonance has been occurring and whether what we observe today is what has always been happening in the Jupiter system. This is because volcanism renews Io’s surface almost constantly, leaving little trace of the past.

Jupiter’s orbital system with the host planet and orbits to scale. Image credit: James Tuttle Keane / Keck Institute for Space Studies

The team of scientists, led by Katherine de Kleer at Caltech and Hughes at GNS Science used the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile observe the sulphur gases in Io’s atmosphere. The isotopes of sulfur were used as a tracer of tidal heating on Io because sulfur is released through volcanism, processed in the atmosphere, and recycled into the mantle. Additionally, some of the sulfur is lost to space, and because of Jupiter’s magnetosphere, a bunch of charged particles whirling around Jupiter that hit Io’s atmosphere continuously.

It turns out that the sulfur that is lost to space on Io is a little bit isotopically lighter than the sulfur that is recycled back into Io’s interior. Because of this, over time, the sulfur remaining on Io gets isotopically heavier and heavier. How much heavier depends on how long volcanism has been taking place.

What the teams found is that tidal heating on Io has been occurring for billions of years.

“The isotopic composition of Io’s inventory of volatile chemical elements, including sulfur and chlorine, reflects its outgassing and mass loss history, and thus records information about its evolution,” the team wrote in the paper published in Science. “These results indicate that Io has been volcanically active for most (or all) of its history, with potentially higher outgassing and mass-loss rates at earlier times.”

Juno continues to makes its way through the Jupiter system. And during Juno’s most recent flyby of Io, on April 9, the spacecraft came within about 16,500 kilometers (10,250 miles) of the moon’s surface. It will perform its 61st flyby of Jupiter on May 12.

JunoCam is a public camera, where members of the public can choose targets for imaging, as well as process all the data.  JunoCam’s raw images are available here for the public to peruse and process into image products. Here you can see the most recent images that have been processed.

Papers: Isotopic Evidence of Long-Lived Volcanism on Io
Using Io’s Sulfur Isotope Cycle to Understand the History of Tidal Heating
Further Reading: NASA, GNS Science

The post Juno Reveals a Giant Lava Lake on Io appeared first on Universe Today.

Categories: Astronomy

What’s the Most Effective Way to Explore our Nearest Stars?

Sat, 04/20/2024 - 6:06am

It was 1903 that the Wright brothers made the first successful self-propelled flight. Launching themselves to history, they set the foundations for transatlantic flights, supersonic flight and perhaps even the exploration of the Solar System. Now we are on the precipice of travel among the stars but among the many ideas and theories, what is the ultimate and most effective way to explore our nearest stellar neighbours? After all, there are 10,000 stars within a region of 110 light years from Earth so there are plenty to choose from. 

It’s not just the stars that entice us to explore beyond our Solar System. Ever since the first exoplanet discovery in 1992 we have been discovering more and more alien worlds around distant stars. The tally has now reached over 5,500 confirmed exoplanets and they too demand our attention as we reach out among the stars. There have been many ideas and technologies proposed over the past few years but to date, even Proxima Centauri (the nearest star system to our own) remains out of reach. 

In his thesis recently published, lead author Johannes Lebert from the Technische Universität München (TUM) attempts to develop a strategy, based on existing interstellar probe concepts and knowledge of nearby star systems. Lebert was driven by the exoplanet discoveries that continue at pace and the development and interest, both commercially and technically in interstellar probes. Not only does he explore the technologies but he also looks at the returns too. 

Artist’s illustration of HD 104067 b, which is the outermost exoplanet in the HD 104067 system, and responsible for potentially causing massive tidal energy on the innermost exoplanet candidate, TOI-6713.01. (Credit: NASA/JPL-Caltech)

In the strategy developed in the thesis he looks at the two main objectives which are duration of the mission and the returns. By returns he refers to the sum of all rewards provided by the stars explored during the mission and of course be largely scientific.  He considers a multi vehicle approach using several probes which do not return to Earth and are capable of exploring different stars thereby maximising the mission returns. Finally he explores the routing of such a mission to ensure maximum mission returns. Succinctly he calls this his ‘Bi-objective multi- vehicle open routing problem with profits.’

The thesis concludes with several recommendation. First that the use of efficient routing around the stars, a more limited number of probes can be used, limiting reducing fuel costs. This should be balanced by the mission returns which increase faster should more probes be used to explore the same number of stars simultaneously. This does however increase mission costs due to increase fuel costs. Whichever strategy is used, small-scale remotely operated or autonomous craft are far more suited to the need. 

Lebert goes on to explain that higher probe numbers also brings the benefit that probes can be tailored to suit the star systems they are destined to explore. Unlike a smaller number of probes that will have to cater for a greater range of systems.  There is a concept known as the ‘derived scaling law’ which articulates that higher probe numbers do inherit a risk of less efficient deployment.

It’s an interesting read that reminds us that, whilst we are developing the probes, and there are quite a number on the drawing board; Breakthrough Starshot, Interstellar Express, Interstellar Probe, Innovative Interstellar Explorer, Tau Mission to name a few, we do need to consider just how we plan, manage and deploy to maximise the scientific gain. 

Source : Optimal Strategies for the Exploration of Near-by Stars

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Categories: Astronomy

Radiating Exoplanet Discovered in “Perfect Tidal Storm”

Fri, 04/19/2024 - 11:45pm

Can tidal forces cause an exoplanet’s surface to radiate heat? This is what a recent study accepted to The Astronomical Journal hopes to address as a team of international researchers used data collected from ground-based instruments to confirm the existence of a second exoplanet residing within the exoplanetary system, HD 104067, along with using NASA’s Transiting Exoplanet Survey Satellite (TESS) mission to identify an additional exoplanet candidate, as well. What’s unique about this exoplanet candidate, which orbits innermost compared to the other two, is that the tidal forces exhibited from the outer two exoplanets are potentially causing the candidates’ surface to radiate with its surface temperature reaching as high as 2,300 degrees Celsius (4,200 degrees Fahrenheit), which the researchers refer to as a “perfect tidal storm”.

Here, Universe Today discusses this fantastic research with Dr. Stephen Kane, who is a Professor of Planetary Astrophysics at UC Riverside and lead author of the study, regarding the motivation behind the study, significant results, the significance of the “tidal storm” aspects, follow-up research, and implications for this system on studying other exoplanetary systems. So, what was the motivation behind this study?

“The star (HD 104067) was a star known to harbor a giant planet in a 55-day orbit, and I have a long history of obsessing over known systems,” Dr. Kane tells Universe Today. “When TESS detected a possible transiting Earth-size planet in a 2.2-day orbit (TOI-6713.01), I decided to examine the system further. We gathered all RV data and found that there is ANOTHER (Uranus mass) planet in a 13-day orbit. So, it started with the TESS data, then the system just kept getting more interesting the more we studied it.”

Dr. Kane’s history of exoplanetary research encompasses a myriad of solar system architectures, specifically those containing highly eccentric exoplanets, but also includes follow-up work after exoplanets are confirmed within a system. Most recently, he was the second author on a study discussing a revised system architecture in the HD 134606 system, along with discovering two new Super-Earths within that system, as well.

For this most recent study, Dr. Kane and his colleagues used data from the High Accuracy Radial velocity Planet Searcher (HARPS) and High Resolution Echelle Spectrometer (HIRES) ground-based instruments and the aforementioned TESS mission to ascertain the characteristics and parameters of both the parent star, HD 105067, and the corresponding exoplanets orbiting it. But, aside from discovering additional exoplanets within the system, as Dr. Kane mentions, what are the most significant results from this study?

Dr. Kane tells Universe Today, “The most amazing outcome of our work was that the dynamics of the system causes the 2.2-day period to experience enormous tidal effects, similar to those experienced by Io. In this case though, TOI-6713.01 experiences 10 million times more tidal energy than Io, resulting in a 2600K [2,300 degrees Celsius (4,200 degrees Fahrenheit)] surface temperature. This means the planet literally glows at optical wavelengths.”

Jupiter’s moon, Io, is the most volcanically active planetary body in the solar system, which is produced from tidal heating caused by Jupiter’s massive gravity throughout Io’s slightly eccentric (elongated) orbit lasting 1.77 days. This means that Io gets closer to Jupiter during certain points and farther away from Jupiter at other points causing Io to compress and expand, respectively. Over millions of years, this constant friction within Io’s interior has led to the heating of its core, resulting in the hundreds of volcanoes that comprise Io’s surface and no visible impact craters, as well. As Dr. Kane mentions, this new exoplanet candidate “experiences 10 million times more tidal energy than Io”, which could raise additional questions regarding its own volcanic activity or other geologic processes. Therefore, what is the significance of the “tidal storm” aspects of TOI-6713.01?

Dr. Kane tells Universe Today, “The reason TOI-6713.01 experiences such strong tidal forces is because of the eccentricity of the outer two giant planets, forcing TOI-6713.01 into an eccentric orbit also. Thus, I referred to the planet as being caught in a perfect tidal storm.”

The HD 104067 system with its two outer giant exoplanets forcing the innermost TOI-6713.01 into a “perfect tidal storm” is slightly reminiscent of Jupiter’s first three Galilean moons, Io, Europa, and Ganymede, regarding their gravitational effects on each other throughout their orbits. There are some differences, however, since Jupiter’s massive gravity is the primary force driving Io’s volcanic activity, and all three moons are in what’s known as orbital resonance, which means the orbits are ratioed with each other. For example, for every four orbits of Io there are two orbits of Europa and one orbit of Ganymede, making their orbital resonance 4:2:1, which results in each moon causing regular gravitational influences on each other. Therefore, with the tidal storm aspect on TOI-6713.01 being caused by the eccentricities of the two outer giants, how does this compare to the relationship between Io, Europa, and Ganymede?

Dr. Kane tells Universe Today, “The Laplace resonance of the Galilean moons creates a particularly powerful configuration, whereby regular alignments of the inner three moons regularly force Io into an eccentric orbit. The HD 104067 system is not in resonance but is still able to produce a power configuration by virtue of the b and c planets being so massive and is therefore more of a “brute force” effect of forcing the inner transiting planet into an eccentric orbit.”

As noted, TOI-6713.01 was discovered using the radial velocity method, also known as Doppler spectroscopy, meaning astronomers measured the miniscule changes in the movement of the parent star as it’s slightly tugged by the planet during the latter’s orbit. These slight changes cause the parent star to wobble as the two bodies tug on each other, and astronomers use a spectrograph to detect changes in these wobbles as the star moves “closer” and “farther away” from us to find exoplanets. This method has proven to be very effective in finding exoplanets, as it accounts for almost 20 percent of the total confirmed exoplanets to date, and the first exoplanet orbiting a star like our own was discovered using this method, as well. However, despite the effectiveness of radial velocity, the study notes how TOI-6713.01 “has yet to be confirmed”, so what additional observations are required to confirm its existence?

Dr. Kanes tells Universe Today, “Because the planet is so small, it’s difficult to detect it from the radial velocity data. However, the transits look clean, and we have ruled out stellar contamination. Additional transits will help, but we’re quite confident in the existence of the planet at this point.”

This study comes as the total number of exoplanetary systems is almost 4,200 with the number of confirmed exoplanets exceeding 5,600 and more than 10,100 exoplanet candidates waiting to hopefully be confirmed, as well. These system architectures have been found to vary widely from our own solar system, which is comprised of the terrestrial (rocky) planets closer to the Sun and the gas giants orbiting much farther out. Examples include hot Jupiters that orbit dangerously close to their parent star, some in only a few days, and other systems boasting seven Earth-sized exoplanets, some of which orbit within the habitable zone. Therefore, what can this unique solar system architecture teach us about exoplanetary systems, overall, and what other exoplanetary systems mirror it?

Dr. Kane tells Universe Today, “This system is a great example of extreme environments that planets can find themselves in. There have been several cases of terrestrial planets that are close to their star and heated by the energy from the star, but very few cases where the tidal energy is melting the planet from within.”

The potential discovery of an exoplanet orbiting in a “perfect tidal storm” further demonstrates the myriad of characteristics that exoplanets and exoplanetary systems exhibit while contrasting with both our own solar system and what astronomers have learned about them until now. If confirmed, TOI-6713.01 will continue to mold our understanding regarding the formation and evolution of exoplanets and exoplanetary systems throughout not only our Milky Way Galaxy, but throughout the cosmos, as well.

“The universe is an amazing place!” Dr. Kane tells Universe Today. “The fun thing about this particular project is that it all started with ‘Hmm … this might be interesting’ then turned into something far more fascinating than I could have imagined! Just goes to show, never miss the chance to follow your curiosity.”

How will this tidal storm exoplanet teach us about other exoplanets and exoplanetary systems in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post Radiating Exoplanet Discovered in “Perfect Tidal Storm” appeared first on Universe Today.

Categories: Astronomy

The Giant Planets Migrated Between 60-100 Million Years After the Solar System Formed

Fri, 04/19/2024 - 11:27am

Untangling what happened in our Solar System tens or hundreds of millions of years ago is challenging. Millions of objects of wildly different masses interacted for billions of years, seeking natural stability. But its history—including the migration of the giant planets—explains what we see today in our Solar System and maybe in other, distant solar systems.

New research shows that giant planet migration began shortly after the Solar System formed.

Planetary migration is a well-established idea. The Grand-Tack Hypothesis says that Jupiter formed at 3.5 AU, migrated inward to 1.5 AU, and then back out again to 5.2 AU, where it resides today. Saturn was involved, too. Migration can also explain the Hot Jupiters we see orbiting extremely close to their stars in other solar systems. They couldn’t have formed there, so they must have migrated there. Even rocky planets can migrate early in a solar system’s history.

New research in the journal Science establishes dates for giant planet migration in our Solar System. Its title is “Dating the Solar System’s giant planet orbital instability using enstatite meteorites.” The lead author is Dr. Chrysa Avdellidou from the University of Leicester’s School of Physics and Astronomy.

“The question is, when did it happen?” Dr. Avdellidou asked. “The orbits of these planets destabilised due to some dynamical processes and then took their final positions that we see today. Each timing has a different implication, and it has been a great matter of debate in the community.”

“What we have tried to do with this work is to not only do a pure dynamical study, but combine different types of studies, linking observations, dynamical simulations, and studies of meteorites.”

The meteorites in this study are enstatites or E-type asteroids. E-type asteroids have enstatite (MgSiO3) achondrite surfaces. Achondrite means they lack chondrules, grains of rock that were once molten before being accreted to their parent body. Specifically, this group of meteorites are the low-iron chondrites called ELs.

When giant planets move, everything else responds. Tiny asteroids are insignificant compared to Jupiter’s mass. Scientists think E-type asteroids were dispersed during the gas giants’ outward migration. They may even have been the impactors in the hypothetical Late Heavy Bombardment.

Artist concept of Earth during the Late Heavy Bombardment period. Scientists have wondered if E-type asteroids disturbed during giant planet migration could’ve been responsible for the Bombardment, but the authors of this research don’t favour that explanation. Credit: NASA’s Goddard Space Flight Center Conceptual Image Lab.

Enstatite achondrites that have struck Earth have similar compositions and isotope ratios as Earth. This signals that they formed in the same part of the protoplanetary disk around the young Sun. Previous research by Dr. Avdellidou and others has linked the meteorites to a population of fragments in the asteroid belt named Athor.

This work hinges on linking meteorites to parent asteroids and measuring the isotopic ratios.

“If a meteorite type can be linked to a specific parent asteroid, it provides insight into the asteroid’s composition, time of formation, temperature evolution, and original size,” the authors explain. When it comes to composition, isotopic abundances are particularly important. Different isotopes decay at different rates, so analyzing their ratio tells researchers when each meteorite closed, meaning when it became cool enough that there was no more significant diffusion of isotopes. “Therefore, thermochronometers in meteorites can constrain the epoch at which major collisional events disturbed the cooling curves of the parent asteroid,” the authors explain.

The team’s research shows that Athor is a part of a once much larger parent body that formed closer to the Sun. It also suffered from a collision that reduced its size out of the asteroid belt.

Athor found its way back when the giant planets migrated. Athor was at the mercy of all that shifting mass and underwent its own migration back into the asteroid belt. Analysis of the meteorites showed that this couldn’t have happened earlier than 60 million years ago. Other research into asteroids in Jupiter’s orbit showed it couldn’t have happened later than 100 million years ago. Since the Solar System formed about 4.56 billion years ago, the giant planet migration happened between 4.5 and 4.46 billion years ago.

This schematic from the research shows what the researchers think happened. Red circles are planetesimals (and their fragments) from the terrestrial planet region. The black solid curves roughly denote the boundary of the current asteroid inner main belt. Eccentricity increases from bottom to top.

A shows the formation and cooling of the EL parent planetesimal in the terrestrial planet region before 60 Myr after Solar System formation. In this period, the terrestrial planets began scattering planetesimals to orbits with high eccentricity and semimajor axes corresponding to the asteroid main belt. B shows that between 60 and 100 Myr, the EL planetesimal was destroyed by an impact in the terrestrial planet region. At least one fragment (the Athor family progenitor) was scattered by the terrestrial planets into the scattered disk, as in (A). Then the giant planet instability implanted it into the inner main belt by decreasing its eccentricity. C shows that a few tens of millions of years after the giant planet instability occurred, a giant impact between the planetary embryo Theia and proto-Earth formed the Moon. D shows that the Athor family progenitor experienced another impact event that formed the Athor family at ~1500 Myr. Image Credit: Avdellidou et al. 2024.

Another important event happened right around the same time. About 4.5 billion years ago, a protoplanet named Theia smashed into Earth, creating the Moon. Could it all be related?

“The formation of the Moon also occurred within the range that we determined for the giant planet instability,” the authors write in their research. “This might be a coincidence, or there might be a causal relationship between the two events.”

“It’s like you have a puzzle, you understand that something should have happened, and you try to put events in the correct order to make the picture that you see today,” Dr. Avdellidou said. “The novelty with the study is that we are not only doing pure dynamical simulations, or only experiments, or only telescopic observations.”

“There were once five inner planets in our Solar System and not four, so that could have implications for other things, like how we form habitable planets. Questions like, when exactly objects came delivering volatile and organics to our planet to Earth and Mars?”

Artist’s impression of the impact that caused the formation of the Moon. Could giant planet migration have caused that impact? Credit: NASA/GSFC

The Solar System’s history is a convoluted, beautiful puzzle that somehow led to us. Everything had to work out for life to arise on Earth, sustain itself, and evolve for so long. The epic migration of the gas giants must have played a role, and this research brings its role into focus.

Never mind habitability, complex life, and civilization, the migration may have allowed Earth to form in the first place.

“The timing is very important because our Solar System at the beginning was populated by a lot of planetesimals,” said study co-author Marco Delbo, Director of Research at France’s Nice Observatory. “And the instability clears them, so if that happens 10 million years after the beginning of the Solar System, you clear the planetesimals immediately, whereas if you do it after 60 million years you have more time to bring materials to Earth and Mars.”

The post The Giant Planets Migrated Between 60-100 Million Years After the Solar System Formed appeared first on Universe Today.

Categories: Astronomy

Artemis Astronauts Will Deploy New Seismometers on the Moon

Thu, 04/18/2024 - 4:14pm

Back in the 1960s and 1970s, Apollo astronauts set up a collection of lunar seismometers to detect possible Moon quakes. These instruments monitored lunar activity for eight years and gave planetary scientists an indirect glimpse into the Moon’s interior. Now, researchers are developing new methods for lunar quake detection techniques and technologies. If all goes well, the Artemis astronauts will deploy them when they return to the Moon.

Fiber optic cable is the heart of a seismology network to be deployed on the Moon by future Artemis astronauts.

The new approach, called distributed acoustic sensing (DAS), is the brainchild of CalTech geophysics professor Zhongwen Zhan. It sends laser beams through a fiber optic cable buried just below the surface. Instruments at either end measure how the laser light changes during the shake-induced tremors. Basically Zhan’s plan turns the cable into a sequence of hundreds of individual seismometers. That gives precise information about the strength and timing of the tremors. Amazingly, a 100-kilometer fiber optic cable would function as the equivalent of 10,000 seismometers. This cuts down on the number of individual seismic instruments astronauts would have to deploy. It probably also affords some cost savings as well.

A seismometer station deployed on the Moon during the Apollo 15 mission. Courtesy NASA. DAS and Apollo on the Moon

Compare DAS the Apollo mission seismometer data and it becomes obvious very quickly that DAS is a vast improvement. In the Apollo days, the small collection of instruments left behind on the Moon provided information that was “noisy”. Essentially, when the seismic waves traveled through different parts of the lunar structure, they got scattered. This was particularly true when they encountered the dusty surface layer. The “noise” basically muddied up the signals.

The layout for the Apollo Lunar Seismic Profiling Experiment for the Apollo 17 mission. Courtesy Nunn, et al. What DAS Does to Detect Quakes on the Moon

The DAS system stations laser emitters and data collectors at each end of a fiber optic cable. This allows for multiple widely spaced installations that measure light as it transits the network. The cable consists of glass strands, and each strand contains tiny imperfections. That sounds bad, but each imperfection provides a useful “waypoint” that reflects a little bit of the light back to the source. That information gets recorded as part of a larger data set. Setting up such a system of telecommunications cables over a large area provides millions of waypoints that scientists can use to measure seismic movements on Earth.

A recent study led by CalTech postdoctoral researcher Qiushi Zhai deployed this type of DAS-enabled fiber optic cable system in Antarctica. The conditions mimic some of the environmental challenges of a lunar deployment—it’s freezing cold, very dry, and far removed from human activities. The sensors measured the small movements of caused by ice cracking and moving around. Those types of signals are perfect analogs to lunar quakes.

Aerial view of Antarctica. A prototype of the lunar DAS system for the Artemis missions to the Moon detected tiny tremors from ice movements here. Photo credit: L. McFadden 2008 Measuring a Lunar Quake Using DAS

Since DAS works well measuring tiny tremors induced by ice, it seems like the perfect “next step” in doing lunar seismology. On the Moon, the fiber optic cable would be buried (just as cables are on Earth) a few centimeters below the level of the regolith. It will sit there waiting for the next quake, which probably won’t take long, since the Moon seems to quiver frequently. When one strikes, its seismic waves will move through the ground from the source. They’ll wiggle the cable. That will affect the light-travel path inside. The actions of light hitting thousands of imperfections inside the cable will provide lunar geologists with high-precision data about moonquakes. That includes their origins, travel time, and other aspects of the wave that will help them understand more about the lunar structure they travel through.

The distributed nature of the seismic network will have a big advantage over the Apollo-style individual seismometers used in the past. And, there are other reasons to use DAS, according to Zhai. “Another advantage of using DAS on the Moon is that a fiber optic cable is physically quite resilient to the harsh lunar environment: high radiation, extreme temperatures, and heavy dust,” Zhai said.

Moon Structure and DAS

Zhai is the first author of a paper describing the DAS system, which should allow scientists to detect close to 100 percent of Moon tremors. The paper offers insight into the advantages that DAS offers. In particular, such an array stretched across large areas of the Moon should provide much higher-quality data about even the smallest tremors that shake the surface.

Since the Moon is not tectonically active, its quakes don’t occur from the same causes as they do on Earth. Some happen during the sunset/sunrise period when temperature changes affect the surface. Others happen thanks to Earth’s pull on the Moon, and still others occur because the Moon is still cooling and contracting. Zhai’s paper suggests that DAS could detect about 15 moonquakes per day, and perhaps help better characterize the thermal moonquakes that happen at sunrise/sunset and the deeper ones that occur during perigee and apogee portions of its orbit, and those intrinsic to the Moon’s contraction. In addition, impacts on the Moon also generate quakes. Information about all these events should give planetary scientists a big leg up on understanding more about the lunar interior structure.

The deployment of DAS and other science experiments will be part of the surface operations of the Artemis missions. It will be part of one of the proposed seven-month stays for astronaut teams. Although there is no specific planned date for seismometer deployment, it’s likely to take place no sooner than the mid-2030s. That’s after the planned missions to build shelters, deploy power stations, and other activities to create the lunar bases.

For More Information

A New Type of Seismic Sensor to Detect Moonquakes
Assessing the feasibility of Distributed Acoustic Sensing (DAS) for Moonquake Detection
Lunar Seismology: A Data and Instrumentation Review

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Categories: Astronomy

Ice Deposits on Ceres Might Only Be a Few Thousand Years Old

Thu, 04/18/2024 - 3:43pm

The dwarf planet Ceres has some permanently dark craters that hold ice. Astronomers thought the ice was ancient when they were discovered, like in the moon’s permanently shadowed regions. But something was puzzling.

Why did some of these shadowed craters hold ice while others did not?

Ceres was first discovered in 1801 and was considered a planet. Later, it was thought to be the first asteroid ever discovered, since it’s in the main asteroid belt. Since then, our expanding knowledge has changed its definition: we now know it as a dwarf planet.

Even though it was discovered over 200 years ago, it’s only in the last couple of decades that we’ve gotten good looks at its surface features. NASA’s Dawn mission is responsible for most of our knowledge of Ceres’ surface, and it found what appeared to be ice in permanently shadowed regions (PSRs.)

New research shows that these PSRs are not actually permanent and that the ice they hold is not ancient. Instead, it’s only a few thousand years old.

The new research is titled “History of Ceres’s Cold Traps Based on Refined Shape Models,” published in The Planetary Science Journal. The lead author is Norbert Schorghofer, a senior scientist at the Planetary Science Institute.

“The results suggest all of these ice deposits must have accumulated within the last 6,000 years or less.”

Norbert Schorghofer, senior scientist, Planetary Science Institute.

Dawn captured its first images of Ceres while approaching the dwarf planet in January 2015. At that time, it was close enough to capture images as good as Hubble’s. Those images showed craters and a high-albedo site on the surface. Once captured by Ceres, Dawn followed a polar orbit with decreasing altitude. It eventually reached 375 km (233 mi) above the surface, allowing it to see the poles and surface in greater detail.

“For Ceres, the story started in 2016, when the Dawn spacecraft, which orbited around Ceres at the time, glimpsed into these permanently dark craters and saw bright ice deposits in some of them,” Schorghofer said. “The discovery back in 2016 posed a riddle: Many craters in the polar regions of Ceres remain shadowed all year – which on Ceres lasts 4.6 Earth years – and therefore remain frigidly cold, but only a few of them harbor ice deposits.”

As scientists continued to study Ceres, they made another discovery: its massive Solar System neighbours make it wobble.

“Soon, another discovery provided a clue why: The rotation axis of Ceres oscillates back and forth every 24,000 years due to tides from the Sun and Jupiter. When the axis tilt is high and the seasons strong, only a few craters remain shadowed all year, and these are the craters that contain bright ice deposits,” said lead author Schorghofer.

This figure from the research shows how Ceres’ obliquity has changed over the last 25,000 years. As the obliquity varies, sunlight reaches some crater floors that were thought to be PSRs. Image Credit: Schorghofer et al. 2023.

Researchers constructed digital elevation maps (DEMs) of the craters to uncover these facts. They wanted to find out how large and deep the shadows in the craters were, not just now but thousands of years ago. But that’s difficult to do since portions of these craters were in deep shadow when Dawn visited. That made it difficult to see how deep the craters were.

Robert Gaskell, also from the Planetary Science Institute, took on the task. He developed a new technique to create more accurate maps of the craters with data from Dawn’s sensitive Framing Cameras, contributed to the mission by Germany. With improved accuracy, these maps of the crater floors could be used in ray tracing to show sunlight penetrated the shadows as Ceres wobbled over thousands of years.

This figure from the study shows some of the DEMs the researchers developed for craters on Ceres. White regions represent sunlit areas, while the coloured contours represent PSRs for different axial tilts. Image Credit: Schorghofer et al. 2023.

The DEMs in the above image show that at 20 degrees obliquity, none of the craters are in permanent shadow. That means none of them have truly permanent PSRs. “A PSR starts to emerge in Bilwis crater at about 18°, and they emerge at lower obliquities at the other six study sites. This implies that the ice deposits are remarkably young,” the researchers write in their paper.

This figure from the research shows PSRs in the north-polar region of Ceres. The colour scale shows how oblique each crater is. The research shows that 14,000 years ago, none of these were PSRs, and the ice they hold now is only 6,000 years old. Image Credit: Schorghofer et al. 2023.

About 14,000 years ago, Ceres reached its maximum axial tilt. At that time, no craters were PSRs. Any ice in these craters would’ve been sublimated into space. “That leaves only one plausible explanation: The ice deposits must have formed more recently than that. The results suggest all of these ice deposits must have accumulated within the last 6,000 years or less. Considering that Ceres is well over 4 billion years old, that is a remarkably young age,” Schorghofer said.

So, where did the ice come from?

There must be some source if the ice is young and keeps reforming during maximum obliquity. The only plausible one is Ceres itself.

“Ceres is an ice-rich object, but almost none of this ice is exposed on the surface. The aforementioned polar craters and a few small patches outside the polar regions are the only ice exposures. However, ice is ubiquitous at shallow depths – as discovered by PSI scientist Tom Prettyman and his team back in 2017 – so even a small dry impactor could vaporize some of that ice.” Schorghofer said. “A fragment of an asteroid may have collided with Ceres about 6,000 years ago, which created a temporary water atmosphere. Once a water atmosphere is generated, ice would condense in the cold polar craters, forming the bright deposits that we still see today. Alternatively, the ice deposits could have formed by avalanches of ice-rich material. This ice would then survive in only the cold shadowed craters. Either way, these events were very recent on an astronomical time scale.”

There are other potential sources of water ice. Ceres has a very thin, transient water atmosphere. The water could come from cryovolcanic processes and then be trapped and frozen in shadowed regions.

Ceres also has a single cryovolcano: Ahuna Mons. It’s at least a couple hundred million years old and long dormant. There are dozens of other dormant potential cryovolcanoes, too. But these likely aren’t the water source.

There’s ample water ice at shallow levels in Ceres. If the dwarf planet erodes over time, mass-wasting could expose and release water that freezes in the craters. “The few ice deposits that have been detected spectroscopically outside the polar regions are indeed often associated with landslides, and the sunlit portion of the ice deposit in Zatik crater is best explained by a recent mass wasting event,” the authors explain.

Ceres has been through a lot. As an ancient protoplanet that’s survived to this day, it holds important clues to the Solar System. Though its craters don’t hold ancient ice like once thought, deeper study is revealing the dwarf planet’s true nature.

“The ice deposits in the Cerean PSRs indicate an active water cycle; ice is either repeatedly captured and lost or frequently exposed, or both,” the authors conclude.

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Categories: Astronomy

The Mystery of Cosmic Rays Deepens

Thu, 04/18/2024 - 1:42pm

Cosmic rays are high-energy particles accelerated to extreme velocities approaching the speed of light. It takes an extremely powerful event to send these bits of matter blazing through the Universe. Astronomers theorize that cosmic rays are ejected by supernova explosions that mark the death of supergiant stars. But recent data collected by the Fermi Gamma-ray space telescope casts doubt on this production method for cosmic rays, and has astronomers digging for an explanation.

It’s not easy to tell where a cosmic ray comes from. Most cosmic rays are hydrogen nuclei, others are protons, or free-flying electrons. These are charged particles, meaning that every time they come across other matter in the Universe with a magnetic field, they change course, causing them to zig-zag through space.

The direction a cosmic ray comes from when it hits Earth, then, is not likely the direction it started in.

But there are ways to indirectly track down their origin. One of the more promising methods is by observing gamma rays (which do travel in straight lines, thankfully).

When cosmic rays bump into other bits of matter, they produce gamma rays. So when a supernova goes off and sends cosmic rays out into the Universe, it should also send a gamma-ray signal letting us know it’s happening.

That’s the theory, anyway.

But the evidence hasn’t matched expectations. Studies of old, distant supernovas show some gamma ray production occurring, but not as much as predicted. Astronomers explained away the missing radiation as a result of the supernovas’ age and distance. But in 2023, the Fermi telescope captured a bright new supernova occurring nearby. Named SN 2023ixf, the supernova went off just 22 million light-years away in a galaxy called Messier 101 (better known as the ‘Pinwheel Galaxy’). And yet again, gamma rays were conspicuously absent.

NASA Goddard.

“Astrophysicists previously estimated that supernovae convert about 10% of their total energy into cosmic ray acceleration,” said Guillem Martí-Devesa, University of Trieste. “But we have never observed this process directly. With the new observations of SN 2023ixf, our calculations result in an energy conversion as low as 1% within a few days after the explosion. This doesn’t rule out supernovae as cosmic ray factories, but it does mean we have more to learn about their production.”

So where is all the missing gamma radiation?

It’s possible that interstellar material around the exploding star could have blocked gamma rays from reaching the Fermi telescope. But it might also mean that astronomers need to look for alternative explanations for the production of cosmic rays.

Nobody likes a good mystery better than astronomers, and digging into the missing gamma radiation could eventually tell us a whole lot more about cosmic rays and where they come from.

Astronomers plan to study SN 2023ixf in other wavelengths to improve their models of the event, and will of course keep an eye out for the next big supernova, in an effort to understand what is going on.

The most recent gamma-ray data from SN 2023ixf will be published in Astronomy and Astrophysics in a paper led by Martí-Devesa.

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Categories: Astronomy

NASA Confirms that a Piece of its Battery Pack Smashed into a Florida Home

Thu, 04/18/2024 - 12:59pm

NASA is in the business of launching things into orbit. But what goes up must come down, and if whatever is coming down doesn’t burn up in the atmosphere, it will strike Earth somewhere.

Even Florida isn’t safe.

Careful consideration goes into releasing debris from the International Space Station. Its mass is measured and calculated so that it burns up during re-entry to Earth’s atmosphere. But in March 2024, something didn’t go as planned.

It all started in 2021 when astronauts replaced the ISS’s nickel hydride batteries with lithium-ion batteries. It was part of a power system upgrade, and the expired batteries added up to about 2,630 kg (5,800 lbs.) On March 8th, 2021, ground controllers used the ISS’s robotic arm to release a pallet full of the expired batteries into space, where orbital decay would eventually send them plummeting into Earth’s atmosphere.

The Canadarm 2 robotic arm releases a pallet of spent batteries into space on March 8th, 2021. Image Credit: NASA

It was the most massive debris release from the ISS. According to calculations, it should have burned up when it entered the atmosphere on March 8th, 2024. But it didn’t.

Alejandro Otero owns a home in Naples, Florida. He wasn’t home on March 8th when there was a loud crash as something smashed into his roof. But his son was. “It was a tremendous sound. It almost hit my son,” Otero told CNN affiliate WINK News in March. “He was two rooms over and heard it all.”

“Something ripped through the house and then made a big hole in the floor and on the ceiling,” Otero explained. “I’m super grateful that nobody got hurt.”

This time, nobody got hurt. But NASA is taking the accident seriously.

Otero cooperated with NASA, and NASA examined the object at the Kennedy Space Center in Florida. They determined the debris was from a stanchion used to mount the old batteries on a special cargo pallet.

This image shows an intact stanchion and the recovered stanchion from the NASA flight support equipment used to mount International Space Station batteries on a cargo pallet. The stanchion survived re-entry through Earth’s atmosphere on March 8, 2024, and impacted a home in Naples, Florida. Image Credit: NASA

The stanchion is made of the superalloy Inconel to understand extreme environments, including extreme heat. It weighs 725 grams (1.6 lbs.) It’s about 10 cm (4 inches) in height and 4 cm (1.6 inches) in diameter.

Even though it’s a tiny object, it’s the type of accident that NASA and the ISS are determined to avoid. “The International Space Station will perform a detailed investigation of the jettison and re-entry analysis to determine the cause of the debris survival and to update modelling and analysis, as needed,” a NASA statement read.

Investigators want to know how the debris survived without burning up on re-entry. Engineers use models to understand how objects react to re-entry heat and break apart, and this event will refine those models. In fact, every time an object reaches the ground, the models are updated.

For Otero, this accident amounted to little more than a great story and an insurance claim. But the chunk of stanchion could’ve seriously injured someone or even killed someone.

In January 1997, Lottie Williams was walking through a park with friends in Tulsa, Oklahoma, in the early morning. They saw a huge fireball in the sky and felt a rush of excitement, thinking they were seeing a shooting star. “We were stunned, in awe,” Williams told FoxNews.com. “It was beautiful.”

Then, something struck her lightly on the shoulder before falling to the ground. It was like a piece of metallic fabric, and after reaching out to some authorities, she learned that it was part of a fuel tank from a Delta II rocket. She’s the first person known to have been hit with space debris. Had it been something with more mass, who knows if Williams would’ve been injured or worse?

That’s why NASA takes debris survival so seriously. The guilt of injuring or even killing someone would be overwhelming. A serious debris accident could also make things very uncomfortable going forward, as people can be fickle and not prone to critical thinking. NASA’s already struggling with budget constraints; the organization doesn’t need any nasty public relations to imperil its progress further.

Complicating matters is that the ESA warned that not all the battery debris would burn up. There wasn’t much else they could do. Fluctuating atmospheric drag made it impossible to predict where debris would strike Earth.

Those who follow space know how complicated and unpredictable this is. And they likewise know how improbable an injury is. But there’s always a non-zero chance of injury or death from space debris for someone going about their life here on the Earth’s surface. If that ever happened, the scrutiny would be intense.

Is it statistical fear-mongering to consider space debris striking someone, injuring them, or worse? Probably. When we see a shooting star in the sky, it’s safe to enjoy the spectacle without worry.

But maybe, just in case, out of an abundance of caution, Don’t Look Up.

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Categories: Astronomy

Are Titan's Dunes Made of Comet Dust?

Thu, 04/18/2024 - 5:37am

A new theory suggests that Titan’s majestic dune fields may have come from outer space. Researchers had always assumed that the sand making up Titan’s dunes was locally made, through erosion or condensed from atmospheric hydrocarbons. But researchers from the University of Colorado want to know: Could it have come from comets?

The dunes of Titan

When the Cassini spacecraft arrived in orbit around Saturn, nobody had ever seen beneath the thick soupy atmosphere of Titan. So when it dropped the Huygens lander, and began probing Titan with cloud-penetrating radar, scientists were surprised to learn that Titan has a very earth-like appearance. It has a thick nitrogen atmosphere, rain, rivers, oceans and massive dune fields. But unlike the dunes of Earth’s sandy deserts in Namibia and southern Arabia, Titan’s dunes are enormous, and fill massive fields covering more than an eighth of the giant moon’s surface. These dunes are about 100 meters tall, 1 to 2 km wide at the base, and can stretch for hundreds of kilometers in length.

Dunes on Earth are made from sand, which is blown by the wind and heaped into drifts. Individual sand particles are nudged and blown by the wind with enough force to make them bounce and scatter in a process called saltation. If the particles don’t bounce, then they cannot pile up on top of each other, but if the wind is able to lift them off the ground completely then they simply blow away. Saltation depends on the size and mass of the sand particles and the strength of the wind, but also needs the particles to be dry so that they can move freely without sticking together.

Titan’s geology

Titan is the second largest moon in the entire Solar System, beaten only by Ganymede, orbiting Jupiter. It is Saturn’s largest moon, and very old. Unlike most of Saturn’s moons, which were captured over time, Titan would have formed together with Saturn billions of years ago. Despite having so many features in common with Earth, it is a very different place. It is so intensely cold that, instead of water, its rain and rivers are made from liquid hydrocarbons like methane. Water, on the other hand, is frozen into hard ice; rocks on Titan are made from water ice, instead of granite and basalt, and Titan’s equivalent of lava and magma are made from liquid water and ammonia.

This means that sand on Titan is not made from silica eroded from larger rocks, since those materials are not found on the surface. One popular theory is that it could instead be made from ice. When liquid methane rains and flows, it could erode the water-ice bedrock, grinding chunks together to a sand of ice grains. An alternative idea is that the sand particles are instead made from tholins. These are found all over the colder regions of the Solar System, where cold hydrocarbons in comets or the outer atmospheres of planets and moons react with ultraviolet light from the Sun to create complex compounds. Tholins formed in the dry atmosphere of Titan could clump together with static electricity to form small grains of soot that then settle to the ground, creating both dust and sand.

Comet 109P/Swift-Tuttle captured during its last pass by Earth on Nov. 1, 1992. Credit: Gerald Rhemann What do comets have to do with this?

A paper presented at this year’s Lunar and Planetary Science Conference (LPSC) suggests a new idea: What if the sand came from comets? Comets, as we know, are made from materials left over from the creation of the Solar System. Most of the primordial gas and dust that collapsed from an ancient nebula to form the Solar System would have ended up in the Sun, with the bulk of the remains forming the planets. But this would still have left a lot of material floating free, and some of that would have gradually coalesced into lumps of dust and ice, which we see today as comets. When comets are nudged into elliptical orbits and pass through the inner Solar System, some of their ice heats up and sublimates into gas which blows out, carrying dust with it. This dust is scattered throughout the Solar System, concentrated along the various comet’s orbits. Individual grains often collide with the Earth, which we see as meteors, burning high in our atmosphere. Recent surveys in Antarctic ice fields, where there is no surface sand, have found many such particles which have survived atmospheric reentry.

But Earth is not the only place where these grains can end up. According to the researchers, there was a time when a great many comets were passing close by Saturn and its moons. They ran simulations to study the evolution of the Kuiper Belt, using a version of the Nice model. The Nice model, named for the city in which it was first presented, says that the Solar System was originally arranged very differently from how it is today. Over time, the planets migrated to their current locations. During this period, Neptune passed through the Kuiper belt, nudging many comets into new orbits. Many of these comets passed close by Saturn and its moons, and some even collided with the moons. The researchers suggest that much of the sand making up Titan’s dunes may be debris from all these comets.

Artist’s concept of Dragonfly soaring over the dunes of Saturn’s moon Titan. Credit: NASA/Johns Hopkins APL/Steve Gribben

But is it true? This idea does fit with what we currently know, and is supported by computer modelling, but so do the other theories. Fortunately, NASA recently confirmed that the Dragonfly mission will be launched in July 2028. Dragonfly is a lander, which will be sent to Titan. But unlike previous missions, this one is an 8-rotor flying drone. Like the rovers on Mars, it will be able to move to any areas of interest that scientists would like to study further. When it arrives in 2034, it will fly to dozens of locations on Titan’s surface, and should settle the question once and for all: Are the dunes of Titan really built from comet dust?


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Categories: Astronomy

The Solar Wind is Stripping Oxygen and Carbon Away From Venus

Wed, 04/17/2024 - 7:55pm

The BepiColombo mission, a joint effort between JAXA and the ESA, was only the second (and most advanced) mission to visit Mercury, the least explored planet in the Solar System. With two probes and an advanced suite of scientific instruments, the mission addressed several unresolved questions about Mercury, including the origin of its magnetic field, the depressions with bright material around them (“hollows”), and water ice around its poles. As it turns out, BepiColombo revealed some interesting things about Venus during its brief flyby.

Specifically, the two probes studied a previously unexplored region of Venus’ magnetic environment when they made their second pass on August 10th, 2021. In a recent study, an international team of scientists analyzed the data and found traces of carbon and oxygen being stripped from the upper layers of Venus’ atmosphere and accelerated to speeds where they can escape the planet’s gravitational pull. This data could provide new clues about atmospheric loss and how interactions between solar wind and planetary atmospheres influence planetary evolution.

The study was led by Lina Hadid, a CNRS researcher at the Plasma Physics Laboratory (LPP) and the Observatoire de Paris. She was joined by researchers from the Institute of Space and Astronautical Science (ISAS) at JAXA, the Max Planck Institute for Solar System Research (MPS), the CNRS Research Institute in Astrophysics and Planetology (IRAP), the Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), the Institute for Geophysics and Extraterrestrial Physics (IGEP), the Space Research Institute (SRI), and multiple universities.

Schematic view of planetary material escaping through Venus magnetosheath flank. Credit: Thibaut Roger/Europlanet 2024 RI/Hadid et al.

While Venus does not have an intrinsic magnetic field like Earth, it has a weak magnetic field that results from the interaction of solar wind and electrically charged particles in Venus’ upper atmosphere. Surrounding this “induced magnetosphere” is the “magnetosheath,” a region where the solar wind is slowed and heated. In August 2021, BepliColombo’s two spacecraft – the ESA’s Mercury Planetary Orbiter (MPO) and JAXA’s Mercury Magnetospheric Orbiter (MMO, aka. Mio) – passed by Venus on the final leg of their journey toward Mercury, using the planet’s gravity to adjust its course and its upper atmosphere to shed speed.

The two spacecraft spent 90 minutes passing through the tail of the magnetosheath and the magnetic regions closest to the Sun. The mission controllers used this opportunity to gather data on the number and mass of charged particles it encountered using Mio‘s Mass Spectrum Analyzer (MSA) and the Mercury Ion Analyzer (MIA), which are part of the probe’s Mercury Plasma Particle Experiment (MPPE). The team also relied on Europlanet’s Sun Planet Interactions Digital Environment on Request (SPIDER) space weather modeling tools to track how atmospheric particles propagated through the magnetosheath.

As Hadid explained in a Europlanet Society release, analysis of this data provides insight into the chemical and physical processes driving atmospheric escape from this region of the magnetosheath:

“This is the first time that positively charged carbon ions have been observed escaping from Venus’s atmosphere. These are heavy ions that are usually slow moving, so we are still trying to understand the mechanisms that are at play. It may be that an electrostatic ‘wind’ is lifting them away from the planet, or they could be accelerated through centrifugal processes.”

In particular, these findings could help scientists to deduce what happened to Venus’ surface water. Like Earth, much of Venus’ surface was once covered in oceans, which disappeared about 700 million years ago. The most widely-held theory is that this coincided with a massive resurfacing event that flooded the atmosphere with carbon dioxide, leading to a runaway Greenhouse Effect that vaporized the oceans. Over time, solar wind stripped away the water, leaving a thick atmosphere over 90 times as dense as Earth’s, and composed of carbon dioxide with smaller amounts of nitrogen and trace gases.

Artist’s impression of Venus with the solar wind flowing around the planet, which has little magnetic protection. Credit: ESA – C. Carreau

Two spacecraft that previously visited Venus – NASA’s Pioneer Venus Orbiter and ESA’s Venus Express -conducted detailed studies of atmospheric loss. However, their orbital paths left some areas unexplored, leaving many questions about the planet’s atmospheric dynamics unanswered. Said Moa Persson, a researcher from the Swedish Institute of Space Physics and a co-author on the study:

“Recent results suggest that the atmospheric escape from Venus cannot fully explain the loss of its historical water content. This study is an important step to uncover the truth about the historical evolution of the Venusian atmosphere, and upcoming missions will help fill in many gaps.”

Over the next decade, several more spacecraft are destined for Venus, including the ESA’s Envision mission, NASA’s Venus Emissivity, Radio Science, InSAR, Topography and Spectroscopy (VERITAS) orbiter and Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) probe, and India’s Shukrayaan orbiter. Collectively, these spacecraft will characterize the Venusian environment, magnetosphere, atmosphere, surface, and interior. This research could lead to improved models that predict how once-habitable planets could become hostile to life as we know it.

Further Reading: Euro Planet Society, Nature Astronomy

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Categories: Astronomy

The Solar Eclipse Like We’ve Never Seen it Before

Wed, 04/17/2024 - 4:23pm

You had to be in the right part of North America to get a great view of the recent solar eclipse. But a particular telescope may have had the most unique view of all. Even though that telescope is in Hawaii and only experienced a partial eclipse, its images are interesting.

You had to be in the right part of North America to get a great view of the recent eclipse. Image Credit: DKIST/NSO/NSF/AURA

The Daniel K. Inouye Solar Telescope (DKIST) is at the Haleakala Observatory in Hawaii. With its four-meter mirror, it’s the largest solar telescope in the world. It observes in visible to near-infrared light, and its sole target is the Sun. It can see features on the Sun’s surface as small as 20 km (12 miles.) It began science operations in February 2022, and its primary objective is to study the Sun’s magnetic fields.

This is a collage of solar images captured by the Inouye Solar Telescope. Images include sunspots and quiet regions of the Sun, known as convection cells. (Credit: NSF/AURA/NSO)

Though seeing conditions weren’t perfect during the eclipse and the eclipse was only partial when viewed from Hawaii, the telescope still gathered enough data to create a movie of the Moon passing in front of the Sun. The bumps on the Moon’s dark edge are lunar mountains.


“The team’s primary mission during Maui’s partial eclipse was to acquire data that allows the characterization of the Inouye’s optical system and instrumentation,” shares National Solar Observatory scientist Dr. Friedrich Woeger.

The Moon plays a critical role in measuring the telescope’s performance. Its edge is well-known and as a dark object in front of the Sun, it acts as a unique tool to measure the Inouye telescope’s performance and to understand the data it collects. Since the telescope has to correct for Earth’s turbulent atmosphere with adaptive optics, the Moon’s known qualities help researchers work with the telescope’s optical elements.

The Daniel Inouye Solar Telescope at the Haleakala Observatory on the Hawaiian island of Maui. Image Credit: DKIST/NSO

“With the Inouye’s high order adaptive optics system operating, the blurring due to the Earth’s atmosphere was greatly reduced, allowing for extremely high spatial resolution images of the moving lunar edge,” said Woeger. “The appearance of the edge is not straight but serrated because of mountain ranges on the Moon!” This serrated dark edge covers the granular convection pattern that governs the “surface of the Sun.”

The Inouye Solar Telescope studies the Sun’s magnetic fields, which drive space weather. What we see in the video is visually interesting, but there’s a lot of data behind it.

It’ll take several months to analyze all of the data it gathered during the eclipse.

The post The Solar Eclipse Like We’ve Never Seen it Before appeared first on Universe Today.

Categories: Astronomy

The Milky Way’s Most Massive Stellar Black Hole is Only 2,000 Light Years Away

Wed, 04/17/2024 - 1:34pm

Astronomers have found the largest stellar mass black hole in the Milky Way so far. At 33 solar masses, it dwarfs the previous record-holder, Cygnus X-1, which has only 21 solar masses. Most stellar mass black holes have about 10 solar masses, making the new one—Gaia BH3—a true giant.

Supermassive black holes (SMBH) like Sagittarius A Star at the heart of the Milky Way capture most of our black hole attention. Those behemoths can have billions of solar masses and have enormous influence on their host galaxies.

But stellar-mass holes are different. Unlike SMBHs that grow massive through mergers with other black holes, stellar black holes result from massive stars exploding as supernovae. SMBHs are always found in the center of a massive galaxy, but stellar black holes can be hidden anywhere.

“This is the kind of discovery you make once in your research life.”

Pasquale Panuzzo, National Centre for Scientific Research (CNRS) at the Observatoire de Paris

Astronomers found BH3 in data from the ESA’s Gaia spacecraft. It’s Gaia’s third stellar black hole. BH3 has a stellar companion, and the black hole’s 33 combined solar masses tugged on its aged, metal-poor companion. The star’s tell-tale wobbling betrayed BH3’s presence. At only 2,000 light-years away, BH3 is awfully close in cosmic terms.

Astronomers have found the most massive stellar black hole in our galaxy, thanks to the wobbling motion it induces on a companion star. This artist’s impression shows the star’s orbits and the black hole, dubbed Gaia BH3, around their common centre of mass. The European Space Agency’s Gaia mission measured this wobbling over several years. Image Credit: ESO/L. Calçada

A new research letter in Astronomy and Astrophysics presented the discovery. Its title is “Discovery of a dormant 33 solar-mass black hole in pre-release Gaia astrometry.” The lead author is Pasquale Panuzzo, an astronomer from the National Centre for Scientific Research (CNRS) at the Observatoire de Paris.

“No one was expecting to find a high-mass black hole lurking nearby, undetected so far,” said Panuzzo. “This is the kind of discovery you make once in your research life.”

This black hole is remarkable for its considerable mass. Researchers have found stellar black holes with similar masses, but always in other galaxies. The size is confounding, but astrophysicists have pieced together how they may become so massive.

They could result from the collapse of metal-poor stars. These stars are composed almost entirely of hydrogen and helium, the primordial elements. Scientists think these stars lose less mass over their lifetimes of fusion than other stars. They retain more mass, so they collapse into more massive black holes. This idea is based on theory; there’s no direct evidence.

But BH3 could change that.

Binary stars tend to form together and have the same metallicity. Follow-up observations showed that BH3’s companion star is likely a remnant of a globular cluster that the Milky Way absorbed more than eight billion years ago. Since binary stars tend to have the same metallicity, this metal-poor companion bolsters the idea that low-metallicity stars can retain more mass and form larger stellar black holes. This is the first evidence supporting the idea that ancient and metal-poor massive stars collapse into massive black holes. It also supports the idea that these early stars may have evolved differently than modern stars of similar masses.

But there’s another interpretation.

Artist’s impression of a Type II supernova explosion, which involves the destruction of a massive supergiant star. When stars explode as supernovae, they eject matter into space, potentially polluting nearby companion stars. Image Credit: ESO

When stars explode as supernovae, they forge heavier elements that are blown out into space. Shouldn’t the companion show evidence of contamination by the metals from BH3’s supernova?

“What strikes me is that the chemical composition of the companion is similar to what we find in old metal-poor stars in the galaxy,” explains Elisabetta Caffau of CNRS, Observatoire de Paris, also a member of the Gaia collaboration. “There is no evidence that this star was contaminated by the material flung out by the supernova explosion of the massive star that became BH3.” From this perspective, the pair may not have formed together. Instead, the black hole could’ve acquired its companion only after its birth, capturing it from another system.

BH3 and the two other black holes found by Gaia are dormant. That means there’s nothing close enough for them to “feed” on. Even though BH3 has a companion, it’s about 16 AU away. If BH3 was actively accreting matter, it would release energy that would betray its presence. Its dormancy enabled it to remain undetected.

Simulation of glowing gas around a spinning black hole. As the gas heats up, it emits energy that makes it visible. If the black hole has no nearby companion, it’s dormant and harder to find. Image Credit: Chris White, Princeton University

At only 2,000 light years away, astronomers are bound to keep studying BH3.

“Finally, the bright magnitude of the system and its relatively small distance makes it an easy target for further observations and detailed analyses by the astronomical community,” the discoverers write in their research letter.

This discovery may have been serendipitous, but it was no accident. A dedicated team of researchers scours Gaia data for stars with odd companions. This includes light and heavy exoplanets, other stars, and black holes. Gaia can’t spot planets or dormant black holes but can spot their effect on their stellar companions.

The researchers behind the discovery released their findings before Gaia’s next official data release. They felt it was too important to sit on. “We took the exceptional step of publishing this paper based on preliminary data ahead of the forthcoming Gaia release because of the unique nature of the discovery,” said co-author Elisabetta Caffau, also a Gaia collaboration member and CNRS scientist from the Observatoire de Paris – PSL.

“We have been working extremely hard to improve the way we process specific datasets compared to the previous data release (DR3), so we expect to uncover many more black holes in DR4,” said Berry Holl of the University of Geneva, in Switzerland, member of the Gaia collaboration.

“This discovery should also be seen as a preliminary teaser for the content of Gaia DR4, which will undoubtedly reveal other binary systems hosting a BH,” the authors conclude.

Gaia DR4 is scheduled to be released no sooner than the end of 2023. If past data releases are any indication, the data will be full of new discoveries. If there are enough binary stellar mass black holes in the data, astronomers may get closer to understanding where they come from and if massive stars behaved differently in the early Universe.

The post The Milky Way’s Most Massive Stellar Black Hole is Only 2,000 Light Years Away appeared first on Universe Today.

Categories: Astronomy

Amazing Amateur Images of April 8th’s Total Solar Eclipse

Wed, 04/17/2024 - 10:07am

The last total solar eclipse across the Mexico, the U.S. and Canada for a generation wows observers.

Did you see it? Last week’s total solar eclipse did not disappoint, as viewers from the Pacific coast of Mexico, across the U.S. from Texas to Maine and through the Canadian Maritime provinces were treated to an unforgettable show. The weather threw us all a curve-ball one week out, as favored sites in Texas and Mexico fought to see the event through broken clouds, while areas along the northeastern track from New Hampshire and Maine onward were actually treated to clear skies.

Many eclipse chasers scrambled to reposition themselves at the last minute as totality approached. In northern Maine, it was amusing to see tiny Houlton, Maine become the epicenter of all things eclipse-based.

A composite of images snapped every five seconds during totality, showing off solar prominences. Credit: György Soponyai observing from Montreal, Canada. Tales of a Total Solar Eclipse

We were also treated to some amazing images of the eclipse from Earth and space. NASA also had several efforts underway to chase the eclipse. Even now, we’re still processing the experience. It takes time (and patience!) for astro-photos to make their way through the workflow. Here are some of the best images we’ve seen from the path of totality:

Tony Dunn had an amazing experience, watching the eclipse from Mazatlan, Mexico. “When totality hit, it didn’t look real,” Dunn told Universe Today. “It looked staged, like a movie studio. the lighting is something that can’t be experienced outside a total solar eclipse.”

Totality on April 8th, with prominences. Credit: Tony Dunn.

Dunn also caught an amazing sight, as the shadow of the Moon moved across the low cloud cover:

#Eclipse2024 #Mazatlan The shadow of the Moon crosses the sky. pic.twitter.com/9FEf4TTK8r

— Tony Dunn (@tony873004) April 14, 2024

Black Hole Sun

Peter Forister caught the eclipse from central Indiana. “It was my second totality (after 2017 in South Carolina), so I knew what was coming,” Forister told Universe Today. “But it was still as incredible and beautiful as anything I’ve ever seen in nature. The Sun and Moon seemed huge in my view—a massive black hole (like someone took a hole punch to the sky) surrounded by white and blue flames streaking out. Plus, there was great visibility of the planets and a few stars. The memory has been playing over and over in my head since it happened—and it’s combined with feelings of awe and wonder at how beautiful our Universe and planet really are. The best kind of memory!”

Totality over Texas. Credit: Eliot Herman

Like many observers, Eliot Herman battled to see the eclipse through clouds. “As you know, we had really frustrating clouds,” Herman told Universe Today. “I shot a few photos (in) which you can see the eclipse embedded in the clouds and then uncovered to show the best part. For me it almost seemed like a cosmic mocking, showing me what a great eclipse it was, and lifting the veil only at the end of the eclipse to show me what I missed…”

Totality and solar prominences seen through clouds. Credit: Eliot Herman Totality Crosses Into Canada

Astrophotographer Andrew Symes also had a memorable view from Cornwall, Ontario. “While I’ve seen many beautiful photos and videos from many sources, they don’t match what those us there in person saw with our eyes,” Symes told Universe Today. “The sky around the Sun was not black but a deep, steely blue. The horizon was lighter–similar to what you’d see during a sunset or sunrise–but still very alien.”

“The eclipsed Sun looked, to me, like an incredibly advanced computer animation from the future! The Sun and corona were very crisp, and the Sun looked much larger in the sky than I’d expected. The eclipsed Sun had almost a three-dimensional quality… almost as if it were a dark, round button-like disk surrounded by a bright halo affixed to a deep blue/grey background. It was as if a ‘worm hole’ or black hole had somehow appeared in front of us. I’m sure my jaw dropped as it was truly a moment of utter amazement. I’m smiling as I type it now… and still awestruck as I recall it in my mind!”

An amazing eclipse. Credit: Andrew Symes. Success for the Total Solar Eclipse in Aroostook County Maine

We were met with success (and clear skies) watching the total solar eclipse with family from our hometown of Mapleton, Maine. We were mostly just visually watching this one, though we did manage to nab a brief video of the experience.

What I was unprepared for was the switch from partial phases to totality. It was abrupt as expected, but there almost seemed to be brief but perceptible pause from day to twilight, as the corona seemed to ‘switch on.’ We all agreed later on that the steely blue sky was not quite night… but not quite twilight, either.

The elusive diamond ring, seen from Wappappello Lake, Missouri on April 8th. Credit: Chris Becke

When’s the next one? I often wonder how many watchers during a given eclipse were ‘bitten by the bug,’ and looking to chase the next one. Spain is set to see an eclipse a year for the next three years, starting in 2026:

Spain is set to become ‘solar eclipse central’ in the coming years, with the next total solar eclipse crossing N. Spain on August 12, 2026, another total solar eclipse on August 2, 2027 crossing the Strait of Gibraltar, and a sunset annular solar eclipse on January 26, 2028. pic.twitter.com/acO4urNG45

— Dave Dickinson (@Astroguyz) April 12, 2024

Spain in August… be sure to stay cool and bring sunblock. Don’t miss the next total solar eclipse, and be thankful for our privileged vantage point in time and space.

The post Amazing Amateur Images of April 8th’s Total Solar Eclipse appeared first on Universe Today.

Categories: Astronomy

Organic Chemistry: Why study it? What can it teach us about finding life beyond Earth?

Wed, 04/17/2024 - 2:28am

Universe Today has recently had the privilege of investigating a myriad of scientific disciplines, including impact cratersplanetary surfacesexoplanetsastrobiologysolar physicscometsplanetary atmospheresplanetary geophysicscosmochemistrymeteorites, radio astronomy, and extremophiles, and how these multidisciplinary fields can help both scientists and space fans better understand how they relate to potentially finding life beyond Earth, along with other exciting facets. Here, we will examine the incredible field of organic chemistry with Dr. Andro Rios, who is an Assistant Professor in Organic Chemistry at San José State University, regarding why scientists study organic chemistry, the benefits and challenges, finding life beyond Earth, and potential paths for upcoming students. So, why is it so important to study organic chemistry?

“Organic chemistry is a fascinating and powerful discipline that is directly connected to nearly everything we interact with on a daily basis,” Dr. Rios tells Universe Today. “This can range from what gives our favorite foods the flavors we love, to the medicines we take to help alleviate our pain. Organic chemistry is also the basis of describing the known chemistry that makes up the biology on this planet (called biochemistry) and can possibly provide the clues to what extraterrestrial life might be based on as well, should we find evidence of it in the upcoming years.”

While its name implies a scientific field of complicated science, the field of organic chemistry essentially involves the study of organic compounds, also known as carbon-based life, which comprises all known lifeforms on the Earth. This involves studying the various properties, classifications, and reactions that comprise carbon-based life, which helps scientists understand their structural formulas and behaviors. This, in turn, enables overlap with other disciplines, including the aforementioned biochemistry, but also includes materials science, polymer chemistry, and medicinal chemistry, as well. Therefore, given its broad range of scientific potential, what are some of the benefits and challenges of studying organic chemistry?

“Organic chemistry has played a vital role in transforming the human experience on this planet by improving our health and longevity,” Dr. Rios tells Universe Today. “All of us, or nearly all of us, have known either family members, friends or even ourselves who have fallen severely ill or battled some chronic disease. The development of new medicines, both directly and indirectly through the tools of organic chemistry to fight these ailments has been one of the most beneficial contributions of this field to society.”

Dr. Rios continues, “Learning organic chemistry in the classroom often presents a challenge because it seems so different from the general chemistry courses that most students have learned to that point. The reason for this is because organic chemistry introduces new terminology, and its focus is heavily tied to the 3-dimensional structure and composition of molecules that is not considered in general chemistry courses. The good news is that organic chemistry provides the perfect bridge from general chemistry to biochemistry/molecular biology which also often focuses on the structures and shapes of molecules (biomolecules).”

The field of organic chemistry was unofficially born in 1807 by the Swedish chemist, Jöns Jacob Berzelius, after he coined the term when describing the origins of living, biological compounds discovered throughout nature. However, this theory was disproven in 1828 by the German scientist, Friedrich Wöhler, who discovered that organic matter could be created within a laboratory setting. It took another 33 years until the German chemist, Friedrich August Kekulé von Stradonitz, officially defined organic chemistry in 1861 as a subfield of chemistry involving carbon compounds. Fast forward more than 160 years later to the present day, and the applications of organic chemistry has expanded beyond the realm of the living and can be found in almost every scientific, industrial, commercial, and medical field throughout the world, including genetics, pharmaceuticals, food, and transportation.

As noted, the very basis of organic chemistry involves the study of carbon-based life, which is the primary characteristic of life on our small, blue world. The reason is because the structure of carbon can form millions of compounds due to their valence electrons that allow it to bond with other elements, specifically hydrogen and oxygen, but can also bond with phosphorus, nitrogen, and sulfur (commonly referred to as CHNOPS).

While carbon-based life is the most common form of life on Earth, the potential for silicon-based life has grabbed the attention of scientists throughout the world due to their similar bonding characteristics as carbon. However, certain attributes, including how it shares electrons (known as electropositivity), prevent it from being able to form lifelike attributes. Therefore, if carbon-based life is currently the primary characteristic of all life on Earth, what can organic chemistry teach us about finding life beyond Earth?

“Life on Earth is highly selective in its utility of organic compounds, both big and small, which is an outcome of biological evolution on this planet,” Dr. Rios tells Universe Today. “But over the years detailed studies on the properties (reactivity, function, preservation, etc) of these molecules and polymers have revealed to us that there is nothing inherently ‘special’ about those biochemicals compared to those that aren’t associated with life (called abiotic chemistry).”

Dr. Rios continues, “What we have learned, however, is that there are trends, or patterns in the selectivity of molecules used by life that might be helpful in informing us not only how life emerged on this planet, but in the search for life elsewhere. This suggests that when we go looking for life in other worlds, we shouldn’t necessarily expect to find the same biochemical make-up we see in our terrestrial biology. Rather, we should be keeping a lookout for any patterns or trends in the chemical make-up of alien environments that are distinct from what we might consider typical abiotic chemistry.”

As noted, the science of organic chemistry is responsible for myriad of applications throughout the world, which are accomplished through the creation of new compounds. One of the most well-known applications for organic chemistry is the pharmaceutical industry and the development of new drugs and treatments, including aspirin which is one of the most well-known drugs throughout the world. Additionally, organic chemistry is responsible for everyday products, including biofuels, biodegradable plastics, agriculture, and environmental purposes. Therefore, with the wide range of applications for organic chemistry, including the potential to find life beyond Earth, what is the most exciting aspect of organic chemistry that Dr. Rios has studied during his career?

“For me, it was when I was in graduate school when I made the realization that I could apply the knowledge and tools of organic chemistry that I was studying in the lab, to questions that were relevant to astrobiology,” Dr. Rios tells Universe Today. “I am particularly interested in questions surrounding prebiotic chemistry, chemical evolution and the origin of life. The primary area that captivates my interest within the origin of life field is metabolic chemistry —exploring the origins of metabolism. This field, known as protometabolic chemistry, has been gaining momentum in recent years. Our community has been uncovering that small prebiotic molecules have the ability, under a wide range of conditions, to initiate simple reaction networks that can lead to more complex molecules over time. These results are exciting because they are potentially helping us understand the origin of one of biology’s most complex processes.”

The individuals who study organic chemistry are aptly called organic chemists who spend time designing and creating new organic compounds for a variety of purposes. This frequently involves examining the myriad of structural drawings of organic compounds and learning how each one functions individually and adding or subtracting new elements to create new compounds. Like most scientific disciplines that Universe Today has examined throughout this series, organic chemistry is successful through the constant collaboration with other fields with the goal of gaining greater insight into life and the world around us, including beyond Earth. Therefore, what advice would Dr. Rios give to upcoming students who wish to pursue studying organic chemistry?

Dr. Rios tells Universe Today, “Organic chemistry is a discipline that fundamentally interacts with so many other fields of STEM; biology, medicine, synthetic biology, bioengineering, chemical engineering, ecology, etc. Taking the time to devote a portion of your education in learning the language of this discipline will be one of the most important intellectual investments you will make in your STEM related career.”

How will organic chemistry help us better understand our place in the cosmos in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post Organic Chemistry: Why study it? What can it teach us about finding life beyond Earth? appeared first on Universe Today.

Categories: Astronomy

The Milky Way’s History is Written in Streams of Stars

Tue, 04/16/2024 - 3:40pm

The Milky Way is ancient and massive, a collection of hundreds of billions of stars, some dating back to the Universe’s early days. During its long life, it’s grown to these epic proportions through mergers with other, smaller galaxies. These mergers punctuate our galaxy’s history, and its story is written in the streams of stars left behind as evidence after a merger.

And it’s still happening today.

The Milky Way is currently digesting smaller galaxies that have come too close. The Large and Small Magellanic Clouds feel the effects as the Milky Way’s powerful gravity distorts them and siphons a stream of gas and stars from them to our galaxy. A similar thing is happening to the Sagittarius Dwarf Spheroidal Galaxy and globular clusters like Omega Centauri.

There’s a long list of these stellar streams in the Milky Way, though the original galaxies that spawned them are long gone, absorbed by the Milky Way. But the streams still tell the tale of ancient mergers and absorptions. They hold kinematic and chemical clues to the galaxies and clusters they spawned in.

As astronomers get better tools to find and study these streams, they’re realizing the streams could tell them more than just the history of mergers. They’re like strings of pearls, and their shapes and other properties show how gravity has shaped them. But they also reveal something else important: how dark matter has shaped them.

Since dark matter is so mysterious, any chance to learn something about it is a priority. As researchers examine the stellar streams, they’re finding signs of disturbances in them—including missing members—that aren’t explained by the Milky Way’s mass. They suspect that dark matter is the cause.

“If we find a pearl necklace with a few scattered pearls nearby, we can deduce that something may have come along and broken the string.”

Soon, astronomers will have an enormously powerful tool to study these streams and dark matter’s role in disturbing them: the Vera Rubin Observatory (VRO).

Astronomers have different methods of studying dark matter. Weak gravitational lensing is one of them, and it maps dark matter on the large scale of galaxy clusters. But stellar streams are at the opposite end of the scale. By mapping them and their irregularities and disturbances, astronomers can study dark matter at a much smaller scale.

This image shows the core of the Sagittarius Dwarf Spheroidal Galaxy and its stellar streams as it’s absorbed by the Milky Way. Image Credit: David Law/UCLA

The Rubin Observatory will complete its Legacy Survey of Space and Time (LSST) in a ten-year period. Alongside its time-domain astronomy objectives, the LSST will also study dark matter. The LSST Dark Energy Science Collaboration is aimed at dark matter and will use Rubin’s power to advance the study of dark energy and dark matter like nothing before it. “LSST will go much further than any of its predecessors in its ability to measure the growth of structure and will provide a stringent test of theories of modi?ed-gravity,” their website explains.

As we get closer and closer to the observatory’s planned first light in January 2025, the growing excitement is palpable.

“I’m really excited about using stellar streams to learn about dark matter,” said Nora Shipp, a postdoctoral fellow at Carnegie Mellon University and co-convener of the Dark Matter Working Group in the Rubin Observatory/LSST Dark Energy Science Collaboration. “With Rubin Observatory we’ll be able to use stellar streams to figure out how dark matter is distributed in our galaxy from the largest scales down to very small scales.”

Astronomers have ample evidence that a halo of dark matter envelops the Milky Way. Other galaxies are the same. These dark matter halos extend beyond a galaxy’s visible disk and are considered basic units in the Universe’s large-scale structure. These haloes may also contain sub-haloes, clumps of dark matter bound by gravity.

This image shows a simulated Milky Way-size CDM halo. The six circles show sub-haloes enlarged in separate boxes. Sub-haloes are also visible, and the bottom row shows several generations of sub-subhaloes contained within subhalo f. Image Credit: Zavala and Frenk 2019

These clumps are what astronomers think are leaving their marks on stellar streams. The dark matter clumps create kinks and gaps in the streams. The VRO has the power to see these irregularities on a small scale and over a ten-year span. “By observing stellar streams, we’ll be able to take indirect measurements of the Milky Way’s dark matter clumps down to masses lower than ever before, giving us really good constraints on the particle properties of dark matter,” said Shipp.

The Lambda Cold Dark Matter (Lambda CDM) model is the standard model of Big Bang Cosmology. One of the Lambda CDM’s key predictions says that many sub-galactic dark matter substructures should exist. Astronomers want to test that prediction by observing these structures’ effect on stellar streams. The VRO will help them do that and will also help them find more of them and build a larger data set.

Stellar streams are difficult to detect. Their kinematics give them away, but sometimes, there are only a few dozen stars in the streams. This obscures them among the Milky Way’s myriad stars. But the VRO will change that.

The VRO will detect streams at much further distances. On the outskirts of the Milky Way, the streams have interacted with less matter, making them strong candidates for studying the effect of dark matter in isolation.

“Stellar streams are like strings of pearls, whose stars trace the path of the system’s orbit and have a shared history,” said Jaclyn Jensen, a PhD candidate at the University of Victoria. Jensen plans to use Rubin/LSST data for her research on the progenitors of stellar streams and their role in forming the Milky Way. “Using properties of these stars, we can determine information about their origins and what kind of interactions the stream may have experienced. If we find a pearl necklace with a few scattered pearls nearby, we can deduce that something may have come along and broken the string.”

The VRO’s powerful digital camera and its system of filters make this possible. Its ultraviolet filter, in particular, will help make more streams visible. Astronomers can distinguish stellar streams from all other stars by examining the blue-ultraviolet light at the end of the visible spectrum. They’ll have thousands upon thousands of images to work with.

Rubin Observatory at twilight in May 2022. Among the observatory’s many endeavours is the study of dark matter. Credit: Rubin Obs/NSF/AURA

In fact, the VRO will unleash a deluge of astronomical data that scientists and institutions have been preparing to handle. AI and machine learning will play a foundational role in managing all that data, which should contribute to finding even more stellar streams.

“Right now it’s a labor-intensive process to pick out potential streams by eye—Rubin’s large volume of data presents an exciting opportunity to think of new, more automated ways to identify streams.”

Astronomers are still finding more stellar streams. Earlier this month, a paper in The Astrophysical Journal presented the discovery of another one. Researchers found it in Gaia’s Data Release 3. It’s likely associated with the merger of the Sequoia dwarf galaxy.

It seems certain that astronomers will keep finding more stellar streams. Their value as tracers of the Milky Way’s history is considerable. But if scientists can use them to understand the distribution of dark matter on a small scale, they’ll get more than they bargained for.

The post The Milky Way’s History is Written in Streams of Stars appeared first on Universe Today.

Categories: Astronomy

The Current Mars Sample Return Mission isn’t Going to Work. NASA is Going Back to the Drawing Board

Tue, 04/16/2024 - 9:55am

Hmmm spaceflight is not the easiest of enterprises. NASA have let us know that their plans for the Mars Sample Return Mission have changed. The original plan was to work with ESA to collect samples from Perseverance and return them to Earth by 2031. Alas like many things, costs were increasing and timescales were slipping and with the budget challenges, NASA has had to rework their plan. Administrator Bill Nelson has now shared a simpler, less expensive and less risk alternative.

The Mars Perseverance Rover departed Earth as part of the Mars 2020 mission on 30 July 2020. It’s no quick nip round the corner to get to the red planet so it arrived just under 7 months later on 18 February 2021. Among its many tasks was to collect rock samples, package them up into tubes and deposit them ready for collection by another future mission to return them to Earth. The samples are to be analysed in Earth based laboratories to help us understand the formation of the Solar System, to look for signs of ancient life on Mars and to enable future human exploration. So far so good but enter NASAs budgetary challenges. 

Illustration of Perseverance on Mars

In response to these budget challenges and to an independent review of the Mars Sample Return mission, NASA have had to get creative. The mission design has been updated to include a simpler, less risky approach and at lower cost. The timescales for the sample return have also now been pushed out to return the samples by 2040 instead of the original target date 9 years earlier. 

The team at NASA are under no illusions as to the complexity of the task at hand. To land safely on Mars is just the beginning. The samples have to be collected and safely stowed away, then the rocket must take off from Mars and return safely to Earth! This has never been done before without human intervention – think Apollo with astronauts bringing several kilograms of lunar samples back for analysis. 

At the time of writing this report, NASA do not yet have a way to reduce the costs yet maintain a high level of confidence of success. NASA has asked multiple teams to work together to come up with a plan that takes an innovative approach with where possible, proven technology. They are to work with other industries on proposals to find ways that the mission can be delivered to the cost challenges, with less complexity and by bringing the delivery of the samples back to the 2030’s. 

Nicky Fox, NASA’s associate administrator from Washington said “NASA does visionary science – and returning diverse, scientifically-relevant samples from Mars is a key priority.” Clearly it’s a challenge, not only the logistics of the mission itself but to bring it in given the constraints facing the team is no mean feat. One thing NASA has on its side is their can-do attitude. It’s an organisation that never fails to impress with ingenious solutions. I have no doubt that, by the end of the 2039 we will see the samples returned to Earth in another first for interplanetary exploration. 

Source : NASA Sets Path to Return Mars Samples, Seeks Innovative Designs

The post The Current Mars Sample Return Mission isn’t Going to Work. NASA is Going Back to the Drawing Board appeared first on Universe Today.

Categories: Astronomy

Peter Higgs Dies at 94

Tue, 04/16/2024 - 6:28am

Just like Isaac Newton, Galileo and Albert Einstein, I’m not sure exactly when I became aware of Peter Higgs. He has been one of those names that anyone who has even the slightest interest in science, especially physics, has become aware of at some point. Professor Higgs was catapulted to fame by the concept of the Higgs Boson – or God Particle as it became known. Sadly, this shy yet key player in the world of physics passed away earlier this month.

Peter Higgs was born on 29th May 1929 in Newcastle upon Tyne. He suffered with asthma as a child and, coupled with the family moving around due to his father’s work, was schooled at home for much of his earlier years. Whilst living in Bristol, Higgs’ father had to move to Bedford so Peter and is Mum stayed behind. Eventually he enrolled in Cotham Grammar School in Bristol where he excelled at science and won many prizes for his work. Surprisingly this tended to focus around chemistry rather than physics. It was at Cotham that he became fascinated by quantum mechanics.

By the time he was 17, he had moved to City of London School and here he focussed on mathematics, eventually graduating with a first-class honours degree in physics. His masters came two years later in 1952. In 1954, he was awarded a PhD with a thesis titled ‘Some Problems in the Theory of Molecular Vibrations from the Universe.’ Higgs tried to get a job at Kings College where he earned his PhD but was unsuccessful so moved to the University of Edinburgh and set about answering the question – Why do some particles have mass?

He worked upon the idea that, at the time when the Universe began, particles did not have mass. This was later gained due to interactions with something which became known as the Higgs Field. The concept was a field that permeates through space giving mass to sub-atomic particles like quarks and leptons. His work was an evolution of earlier work from Yoichiro Nambu from the University of Chicago.

Two other groups of scientists published work at similar times with a similar concept, but Higgs’ work published in 1964 was prominent and so the (theoretical) particle, that transferred mass, became known as the Higgs Boson. In the years that followed, scientists hunted for the new particle, chiefly using the Large Hadron Collider at CERN but Higgs retired by 2006 with nothing detected.

The Hadron Collider is a particle accelerator that had been built to simulate conditions equivalent to billionths of a second after the Big Bang. By crashing subatomic particles together and observing the interactions, scientists can probe the very nature of matter. It cost $10bn and it was this that scientists hoped would prove, or otherwise Higgs’ theory.

In 2012, Higgs received word from CERN at the collider ‘Peter should come to the CERN event or he will regret it!’ Higgs went along and to his delight and amazement, and at the age of 83 and 48 years after he published his theory, he heard that the Higgs Boson had finally been discovered. Higgs later said “It’s been a long wait but it might have been even longer, I might not have been still around. At the beginning I had no idea whether a discovery would be made in my lifetime.”

The discovery changed the face of physics and it was this that led to being awarded a Nobel Prize. Higgs didn’t own a mobile phone though and he found out about his award when a neighbour stopped him in the street to congratulate him. It is clear though that Higgs was in it for the science and not the fame that came with his groundbreaking discovery. He was a man who was often referred to as shy and retiring and he will be a great loss to the world of Physics. Professor Higgs died on 8th April 2021.

The post Peter Higgs Dies at 94 appeared first on Universe Today.

Categories: Astronomy

More Views of the 2024 Eclipse, from the Moon and Earth Orbit

Tue, 04/16/2024 - 12:49am

It’s been just over a week since millions of people flocked to places across North America for a glimpse of moonshadow. The total solar eclipse of April 8th, 2024 was a spectacular sight for many on the ground. From space, however, it was even more impressive as Earth-observing satellites such as GOES-16 captured the sight of the shadow sweeping over Earth.

NASA even got a snap of the eclipse from the Moon, as taken by the Lunar Reconnaissance Orbiter Camera (LROC). Unlike most Earth-based photographers, however, LROC’s view was a tricky one to get. The cameras are line scanners and their images get built up line-by-line. That process requires the spacecraft to slew to keep up with the action and build up a complete view. Amazingly, it took only 20 seconds to capture all the action.

A short video of the eclipse shadow along the path of totality, captured by NASA’s Deep Space Climate Observatory.

NASA’s Deep Space Climate Observatory got an amazing view from Earth orbit, capturing the entire eclipse as it passed over the continent. That observatory “lives” out at LaGrange Point 1, which enabled it to get a full view of Earth and the Moon’s shadow.

Eclipse as Experience

For most viewers, the chase to see an eclipse meant driving (or flying) to somewhere along the path of totality to get the best view. That path stretched from the Pacific Ocean off the coast of Mexico up toward the northern Canadian provinces. That meant a wide swath of the U.S. experienced totality. Or course, the weather had to be good to see it all. In most places, that actually turned out reasonably well. Social media immediately came alive with images of the eclipse, people enjoying it, and others waiting vainly for a break in the clouds.

A composite of images taken during the total solar eclipse showing all the phases leading up to and after totality. NASA/Keegan Barber.

This writer was stationed off the coast of Mazatlán, Mexico, on a cruise ship with a group of amateur and professional astronomers. Although there were a few clouds, the view of the eclipsed Sun was nearly pristine. From the ship, everyone was able to watch the shadow approach, feel the temperature drop, and marvel at 4 minutes and 20 seconds of totality.

A projection of the partially eclipsed Sun on the stack of a cruise ship off the coast of Mazatlan. Image credit: Carolyn Collins Petersen.

In a few regions, however, people were only able to watch clouds get dark. And, for the majority of viewers outside of the path of totality, they could only get a partial view. Still, in many places, people went out to experience the event using eclipse glasses or pinhole projection methods to see those partial phases.

Eclipse from the Air

For those who could “fly the eclipse” it was an opportunity to take a jet plane along the path and prolong the experience. During the eclipse, flight-tracking apps showed a huge increase in traffic along the path. Several airlines had flights that tracked the path, giving lucky passengers the view of a lifetime for a short period.

A pilot flying a WB-57 jet during the total solar eclipse on April 8, 2024. Credit: NASA/Mallory Yates

At least one NASA jet pilot captured a view as the aircraft passed through the shadow. In space, the astronauts aboard the International Space Station got a great shot of the umbra and penumbra passing over the maritime provinces of Canada.

A view of the eclipse shadow from the International Space Station. Courtesy NASA. Future Eclipses

The 2024 eclipse across North America left many with a taste for more moonshadow experience. Unfortunately, that was the last one for this part of the world until 2045. That’s when another one will sweep across the continent. Before that, however, there are other total solar eclipses, as well as lunar and annular events. The years 2026, 2027, and 2028 will feature totalities across parts of Europe, Egypt, and Australia. You can find out locations and dates for others at Mr. Eclipse, as well as NASA’s own eclipse site. For each event, there’ll be plenty of information about safe viewing, as well as “broadcasts” on social media for those outside of the paths of totality.

For More Information

2024 Eclipse as Seen From The Moon
The April 8 Total Solar Eclipse: Through the Eyes of NASA

The post More Views of the 2024 Eclipse, from the Moon and Earth Orbit appeared first on Universe Today.

Categories: Astronomy