Universe Today

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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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?

https://www.hou.usra.edu/meetings/lpsc2024/pdf/1550.pdf

The post Are Titan's Dunes Made of Comet Dust? appeared first on Universe Today.

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

The post The Solar Wind is Stripping Oxygen and Carbon Away From Venus appeared first on Universe Today.

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.

via GIPHY

“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.

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.

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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.

Universe Today has recently had the privilege of investigating a myriad of scientific disciplines, including impact craters, planetary surfaces, exoplanets, astrobiology, solar physics, comets, planetary atmospheres, planetary geophysics, cosmochemistry, meteorites, 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!

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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.

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.

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.

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.

I’m really not sure what to call it but a ‘dusty sneeze’ is probably as good as anything. We have known for some years that stars surround themselves with a disk of gas and dust known as the protostellar disk. The star interacts with it, occasionally discharging gas and dust regularly. Studying the magnetic fields revealed that they are weaker than expected. A new proposal suggests that the discharge mechanism ‘sneezes’ some of the magnetic flux out into space. Using ALMA, the team are hoping to understand the discharges and how they influence stellar formation. 

In a fairly inconspicuous part of the Galaxy, a star slowly formed out of a cloud of gas and dust. This event took place around 4.6 billion years ago and soon, the hot young star began to clear the surrounding area of gas and dust. What remained was a disk surrounding the star known as a protostellar disk. Eventually the planets of our Solar System formed. It is not unique to our own system though as there have been disks like this found around many stars. A very well known example are the stars in the Trapezium cluster inside the Orion Nebula. 

Behind the Gas and Dust of Orion’s Trapezium Cluster

A team in Japan, from the Kyushu University have been examining data from the ALMA radio telescope to learn more about stars in the earliest stages of development. To their surprise they discovered the disks around new stars seem to emit jets or plumes of dust and gas and even electromagnetic energy. The team dubbed them ‘sneezes’ and its this process that seems to slowly erode the magnetic flux of a young star system. 

ALMA’s high-resolution images of nearby protoplanetary disks, which are results of the Disk Substructures at High Angular Resolution Project (DSHARP). The observatory is often used to look for planet birth clouds like these and the one around HD 169142. Credit: ALMA (ESO/NAOJ/NRAO), S. Andrews et al.; NRAO/AUI/NSF, S. Dagnello

One phenomenon of the disks is a powerful magnetic field which permeates through the region. It therefore carries a magnetic flux and herein lies the problem. The magnetic fields would be far stronger than those observed if the magnetic flux had been retained from day one. History shows us, they didn’t seem to retain them so the flux has been slowly eroded away in new star and planetary systems. 

One such proposal was that the field slowly decreased as the surrounding dust cloud collapsed into the core of the star. To explore the phenomenon the team studied MC 27, a system 450 light years away using ALMA, the Atacama Large Millimetre Array. In total, 66 radio telescopes pointed to the object from an altitude of 5,000 metres. They found that there were ‘spike like’ structures that seemed to extend out by a few astronomical units (average distance between Sun and Earth.)

The Atacama Large Millimeter/submillimeter Array (ALMA). Credit: C. Padilla, NRAO/AUI/NSF

The team found that the features contained gas and dust but had a magnetic flux. Known as ‘interchange instability’, the field exhibits instabilities when it reacts with different densities of gas. They referred to these, not as interchange instability but as a baby star’s sneeze. Just like a human sneeze which expels dust and gas or rather air from our bodies, so a young hot star ‘sneezing’ releases gas and dust from the disk. 

Further exploration revealed signs of other plumes several thousands of astronomical units from the protostellar disk. They suggest that these are evidence of other sneezes in the past. It’s not just on MC 27 though, the spikes have been seen in other star systems but more time is needed to be able to fully understand the implications of the discovery. 

Source : Twinkle twinkle baby star, ‘sneezes’ tell us how you are

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The most recognizable feature on Pluto is its “heart,” a relatively bright valentine-shaped area known as Tombaugh Regio. How that heart got started is one of the dwarf planet’s deepest mysteries — but now researchers say they’ve come up with the most likely scenario, involving a primordial collision with a planetary body that was a little more than 400 miles wide.

The scientific term for what happened, according to a study published today in Nature Astronomy, is “splat.”

Astronomers from the University of Bern in Switzerland and the University of Arizona looked for computer simulations that produced dynamical results similar to what’s seen in data from NASA’s New Horizons probe. They found a set of simulations that made for a close match, but also ran counter to previous suggestions that Pluto harbors a deep subsurface ocean. They said their scenario doesn’t depend on the existence of a deep ocean — which could lead scientists to rewrite the history of Pluto’s geological evolution.

An artist’s conception shows the presumed collision of a planetary body with Pluto. (Thibaut Roger/University of Bern)

University of Arizona astronomer Adeene Denton, one of the study’s co-authors, said the formation of the heart “provides a critical window into the earliest periods of Pluto’s history.”

“By expanding our investigation to include more unusual formation scenarios, we’ve learned some totally new possibilities for Pluto’s evolution,” Denton said in a news release. Similar scenarios could apply to other objects in the Kuiper Belt, the ring of icy worlds on the edge of our solar system.

The study focuses on the western half of the heart, a roughly 1,000-mile-wide, teardrop-shaped region called Sputnik Planitia. That region contains an assortment of ices and is roughly 2.5 miles lower in elevation than the rest of Pluto. It’s clearly the result of a massive impact.

“While the vast majority of Pluto’s surface consists of methane ice and its derivatives, covering a water-ice crust, the Planitia is predominantly filled with nitrogen ice which most likely accumulated quickly after the impact due to the lower altitude,” said study lead author Harry Ballantyne, a research associate at the University of Bern.

The eastern half of the heart is covered by a similar but much thinner layer of nitrogen ice. The origins of that part of Tombaugh Regio are still unclear, but it’s probably related to the processes that shaped Sputnik Planitia.

Ballantyne and his colleagues ran a wide assortment of computer simulations for the ancient impact. Those simulations reflected a range of sizes and compositions for the impacting body, at different velocities and angles of approach. The best fit for Sputnik Planitia’s shape involved a 400-mile-wide object, composed of 15% rock, coming in at an angle of 30 degrees and hitting Pluto at a relatively low velocity.

Based on those parameters, the object would have plowed through Pluto’s surface with a splat. The resulting shape wouldn’t look like your typical impact crater. Instead, it would look like a bright, icy teardrop, with the rocky core of the impacting body ending up at the tail of the teardrop.

“Pluto’s core is so cold that the rocks remained very hard and did not melt despite the heat of the impact, and thanks to the angle of impact and the low velocity, the core of the impactor did not sink into Pluto’s core, but remained intact as a splat on it,” Ballantyne explained.

Previous scenarios for Sputnik Planitia’s origin relied on the presence of a deep ocean beneath Pluto’s surface to explain why the impact region hasn’t drifted toward Pluto’s nearest pole over time. But the researchers behind the newly published study found that the best matches in their simulations called for an ocean measuring no more than 30 miles in depth. “If the influence of ammonia proves negligible, Pluto might not possess a subsurface ocean at all, in accordance with our nominal case,” they wrote.

The researchers say they’ll continue their work to model Pluto’s geological history — and how those models could apply to other Kuiper Belt objects as well.

Meanwhile, the New Horizons spacecraft is continuing its journey through the solar system’s far reaches, nearly nine years after its Pluto flyby. Mission scientists recently reported detecting higher than expected levels of interplanetary dust, which suggests there may be more to the Kuiper Belt than they thought. They’re hoping to identify yet another icy world that the spacecraft can observe up close in the late 2020s or the 2030s.

In addition to Ballantyne and Denton, the authors of the Nature Astronomy study, titled “Sputnik Planitia as an Impactor Remnant Indicative of an Ancient Rocky Mascon in an Oceanless Pluto,” include Erik Asphaug, Alexandre Emsenhuber and Martin Jutzi.

The post How Did Pluto Get Its Heart? Scientists Suggest an Answer appeared first on Universe Today.

Look through the names and origins of the constellations and you will soon realise that many cultures had a hand in their conceptualisation. Among them are the Egyptians who were fantastic astronomers. The movement of the sky played a vital role in ancient Egypt including the development of the 365 day year and the 24 hour day. Like many other cultures they say the Sun, Moon and planets as gods. Surprisingly though, the bright Milky Way seems not to have played a vital role. Some new research suggests that this may not be the case and it may have been a manifestation of the sky goddess Nut! 

It’s a fairly well accepted theory that the pyramids of Egypt were constructed in some way as a representation of or tribute to the sky. The Sun god Ra was often depicted sailing the Sun across the sky in a boat but the Milky Way was never seemed to be a big part, other than perhaps some consideration that the river Nile could represent it. 

Nile River, Lake Nasser and the Red Sea, Egypt

Back in the days of ancient Egypt, light pollution really wasn’t a thing. The Milky Way would have been far more prominent than for many stargazers today. A recent study by astrophysicists at the University of Portsmouth suggest that a lesser heard god by the name of Nut had something to do with it. 

Hunt through Egyptian artwork and you will often see a star-filled woman arched over another person. The woman is Nut, the goddess of the sky and the other figure represents her brother, the god of Earth, Geb. Nut has a very specific job though, she protects the Earth from being flooded from waters of the void! Presumably this would be the void of space but of course back then we didn’t have such a great understanding of the cosmos. She also swallowed the Sun as it sets, giving birth to it again in the morning. 

Thankfully the Egyptians were fabulous at recording things and so there have been plenty of Egyptian texts to refer to. Running simulations from the evidence in the documents, the team (led by Dr Or Graur Associate Professor in Astrophysics) suggest that the Milky Way represented Nut’s outstretched arms in the winter and her backbone in the summer. This suggestion aligns with the broad patterns in the Milky Way. 

The arch of the Milky Way seen over Bisei Town in Japan. It prides itself on its dark skies, but faces scattered light pollution from other nearby municipalities. Courtesy DarkSky.Org.

Dr Graur went on to explain that their results revealed that Nut had far more of a functional role too. She was involved in the transition of deceased souls to the afterlife and had a connection with annual bird migrations. This is in line with many cultures like those in North and Central America believing the Milky Way was a road used by spirits or those in Finland and the Baltics who believed it was a path for birds. 

Source : The hidden role of the Milky Way in ancient Egyptian mythology

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In 2011, astronomers with the Wide Angle Search for Planets (WASP) consortium detected a gas giant orbiting very close to a Sun-like (G-type) star about 700 light-years away. This planet is known as WASP-39b (aka. “Bocaprins”), one of many “hot Jupiters” discovered in recent decades that orbits its star at a distance of less than 5% the distance between the Earth and the Sun (0.05 AU). In 2022, shortly after the James Webb Space Telescope (JWST) it became the first exoplanet to have carbon dioxide and sulfur dioxide detected in its atmosphere.

Alas, researchers have not constrained all of WASP-39b’s crucial details (particularly its size) based on the planet’s light curves, as observed by Webb. which is holding up more precise data analyses. In a new study led by the Max Planck Institute for Solar System Research (MPS), an international team has shown a way to overcome this obstacle. They argue that considering a parent star’s magnetic field, the true size of an exoplanet in orbit can be determined. These findings are likely to significantly impact the rapidly expanding field of exoplanet study and characterization.

The study was led by Dr. Nadiia M. Kostogryz and her fellow researchers from the MPS. They were joined by astronomers and astrophysicists from the Center for Astronomy (Heidelberg University), the Astrophysics Group at Keele University, the Kavli Institute for Astrophysics and Space Research at the Massachusetts Institute of Technology (MIT), and the Space Telescope Science Institute (STScI). The paper describing their research, “Magnetic origin of the discrepancy between stellar limb-darkening models and observations,” was recently published in Nature Astronomy.

The “hot Jupiter” exoplanet WASP-69b orbits its star so closely that its atmosphere is being blown into space. Credit: Adam Makarenko/W. M. Keck Observatory

A light curve is the measurement of a star’s brightness over longer periods. Using the Transit Method (Transit Photometry), astronomers monitor stars for periodic dips in brightness, which can result from an exoplanet passing (transiting) in front of their face relative to the observer. In addition to being the most widely used method for detecting exoplanets, precise observations of light curves allow astronomers to estimate the size and orbital period of the exoplanets.

These curves can also reveal information about the composition of the planet’s atmosphere based on light passing through its atmosphere as it makes a transit – a technique known as “transit spectroscopy.” Unfortunately, estimates on planet size suffer from an observational issue known as “limb darkening.” Dr. Kostogryz explained in an MPS press statement:

“The problems arising when interpreting the data from WASP-39b are well known from many other exoplanets – regardless [of] whether they are observed with Kepler, TESS, James Webb, or the future PLATO spacecraft. As with other stars orbited by exoplanets, the observed light curve of WASP-39 is flatter than previous models can explain.”

The edge of the stellar disk (or “limb”) plays a decisive role in interpreting a star’s light curve. Since the limb corresponds to the star’s outer (and cooler) layers, it appears darker to the observer than the inner area. However, the star does not actually shine less brightly further out. This “limb darkening” affects the shape of the exoplanet signal in the light curve, as the dimming determines how steeply the curve falls during a planetary transit and then rises again. Historically, astronomers have not been able to reproduce observational data using conventional stellar models accurately.

In every case, the decrease in the star’s brightness was less abrupt than model calculations predicted. Clearly, something was missing from the models that prevented astronomers from reproducing exoplanet transit signals. As Dr. Kostogryz and her team discovered, the missing piece is stellar magnetic fields, which are generated by the motion of conductive plasma inside a star. The team first noticed this when examining selected light curves obtained by NASA’s Kepler Space Telescope between 2009 and 2018.

An illustration of Earth’s magnetic field. Credit: ESA/ATG medialab

The researchers also proved that the discrepancy between observational data and model calculations disappears if the star’s magnetic field is included in the computations. To this end, the team turned to selected data from NASA’s Kepler Space Telescope, which captured the light of thousands and thousands of stars from 2009 to 2018. To this end, they modeled the atmosphere of typical Kepler stars in the presence of a magnetic field and then simulated observational data based on these calculations. When they compared their results to real data, they found it accurately reproduced Kepler’s observations.

They also found that the strength of the magnetic field can have a profound effect, where limb darkening is more pronounced in stars with weak magnetic fields and less in stars with strong ones. Lastly, they extended their simulations to emission spectra data obtained by the JWST and found that the magnetic field of the parent star influences limb darkening differently at different wavelengths. These findings will help inform future exoplanet studies, leading to more precise estimates of the planets’ characteristics. Said Dr. Alexander Shapiro, coauthor of the current study and head of an ERC-funded research group at the MPS:

“In the past decades and years, the way to move forward in exoplanet research was to improve the hardware, the space telescopes designed to search for and characterize new worlds. The James Webb Space Telescope has pushed this development to new limits. The next step is now to improve and refine the models to interpret this excellent data.”

The researchers now plan to extend their analyses to stars different from the Sun, which could lead to refined estimates of exoplanet mass for rocky planets (similar to Earth). In addition, their findings indicate that the light curves of stars could be used to constrain the strength of stellar magnetic fields, another characteristic that is challenging to measure.

Further Reading: MPS, Nature Astronomy

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An international research team led by the University of Vienna has made a major breakthrough. In a study recently published in Nature Astronomy, they describe how they conducted the first direct measurements of stellar wind in three Sun-like star systems. Using X-ray emission data obtained by the ESA’s X-ray Multi-Mirror-Newton (XMM-Newton) of these stars’ “astrospheres,” they measured the mass loss rate of these stars via stellar winds. The study of how stars and planets co-evolve could assist in the search for life while also helping astronomers predict the future evolution of our Solar System.

The research was led by Kristina G. Kislyakova, a Senior Scientist with the Department of Astrophysics at the University of Vienna, the deputy head of the Star and Planet Formation group, and the lead coordinator of the ERASMUS+ program. She was joined by other astrophysicists from the University of Vienna, the Laboratoire Atmosphères, Milieux, Observations Spatiales (LAMOS) at the Sorbonne University, the University of Leicester, and the Johns Hopkins University Applied Physics Laboratory (JHUAPL).

Astrospheres are the analogs of our Solar System’s heliosphere, the outermost atmospheric layer of our Sun, composed of hot plasma pushed by solar winds into the interstellar medium (ISM). These winds drive many processes that cause planetary atmospheres to be lost to space (aka. atmospheric mass loss). Assuming a planet’s atmosphere is regularly replenished and/or has a protective magnetosphere, these winds can be the deciding factor between a planet becoming habitable or a lifeless ball of rock.

Logarithmic scale of the Solar System, Heliosphere, and Interstellar Medium (ISM). Credit: NASA-JPL

While stellar winds mainly comprise protons, electrons, and alpha particles, they also contain trace amounts of heavy ions and atomic nuclei, such as carbon, nitrogen, oxygen, silicon, and even iron. Despite their importance to stellar and planetary evolution, the winds of Sun-like stars are notoriously difficult to constrain. However, these heavier ions are known to capture electrons from neutral hydrogen that permeates the ISM, resulting in X-ray emissions. Using data from the XXM-Newton mission, Kislyakova and her team detected these emissions from other stars.

These were 70 Ophiuchi, Epsilon Eridani, and 61 Cygni, three main sequence Sun-like stars located 16.6, 10.475, and 11.4 light-years from Earth (respectively). Whereas 70 Ophiuchi and 61 Cygni are binary systems of two K-type (orange dwarf) stars, Epsilon Eridani is a single K-type star. By observing the spectral lines of oxygen ions, they could directly quantify the total mass of stellar wind emitted by all three stars. For the three stars surveyed, they estimated the mass loss rates to be 66.5±11.1, 15.6±4.4, and 9.6±4.1 times the solar mass loss rate, respectively.

In short, this means that the winds from these stars are much stronger than our Sun’s, which could result from the stronger magnetic activity of these stars. As Kislyakova related in a University of Vienna news release:

“In the solar system, solar wind charge exchange emission has been observed from planets, comets, and the heliosphere and provides a natural laboratory to study the solar wind’s composition. Observing this emission from distant stars is much more tricky due to the faintness of the signal. In addition to that, the distance to the stars makes it very difficult to disentangle the signal emitted by the astrosphere from the actual X-ray emission of the star itself, part of which is “spread” over the field-of-view of the telescope due to instrumental effects.”

XMM-Newton X-ray image of the star 70 Ophiuchi (left) and the X-ray emission from the region (“Annulus”) surrounding the star represented in a spectrum over the energy of the X-ray photons (right). Credit: C: Kislyakova et al. (2024)

For their study, Kislyakova and her team also developed a new algorithm to disentangle the contributions made by the stars and their astrospheres to the emission spectra. This allowed them to detect charge exchange signals from the stellar wind oxygen ions and the neutral hydrogen in the surrounding ISM. This constitutes the first time X-ray charge exchange emissions from the extrasolar astrospheres have been directly detected. Moreover, the mass loss rate estimates they derived could be used by astronomers as a benchmark for stellar wind models, expanding on what little observational evidence there is for the winds of Sun-like stars. As co-author Manuel Güdel, also of the University of Vienna, indicated:

“There have been world-wide efforts over three decades to substantiate the presence of winds around Sun-like stars and measure their strengths, but so far only indirect evidence based on their secondary effects on the star or its environment alluded to the existence of such winds; our group previously tried to detect radio emission from the winds but could only place upper limits to the wind strengths while not detecting the winds themselves. Our new X-ray based results pave the way to finding and even imaging these winds directly and studying their interactions with surrounding planets.”

In the future, this method of direct detection of stellar winds will be facilitated by next-generation missions like the European Athena mission. This mission will include a high-resolution X-ray Integral Field Unit (X-IFU) spectrometer, which Athena will use to resolve the finer structure and ratio of faint emission lines that are difficult to distinguish using XMM-Newton’s instruments. This will provide a more detailed picture of the stellar winds and astrospheres of distant stars, helping astronomers constrain their potential habitability while also improving solar evolution models.

Further Reading: University of Vienna, Nature Astronomy

The post Stellar Winds Coming From Other Stars Measured for the First Time appeared first on Universe Today.

One of the big mysteries about dark matter particles is whether they interact with each other. We still don’t know the exact nature of what dark matter is. Some models argue that dark matter only interacts gravitationally, but many more posit that dark matter particles can collide with each other, clump together, and even decay into particles we can see. If that’s the case, then objects with particularly strong gravitational fields such as black holes, neutron stars, and white dwarfs might capture and concentrate dark matter. This could in turn affect how these objects appear. As a case in point, a recent study looks at the interplay between dark matter and neutron stars.

Neutron stars are made of the most dense matter in the cosmos. Their powerful gravitational fields could trap dark matter and unlike black holes, any radiation from dark matter won’t be trapped behind an event horizon. So neutron stars are a perfect candidate for studying dark matter models. For this study, the team looked at how much dark matter a neutron star could capture, and how the decay of interacting dark matter particles would affect its temperature.

The details depend on which specific dark matter model you use. Rather than addressing variant models, the team looked at broad properties. Specifically, they focused on how dark matter and baryons (protons and neutrons) might interact, and whether that would cause dark matter to be trapped. Sure enough, for the range of possible baryon-dark matter interactions, neutron stars can capture dark matter.

The team then went on to look at how dark matter thermalization could occur. In other words, as dark matter is captured it should release heat energy into the neutron star through collisions and dark matter annihilation. Over time the dark matter and neutron star should reach a thermal equilibrium. The rate at which this occurs depends on how strongly particles interact, the so-called scattering cross-section. The team found that thermal equilibrium is reached fairly quickly. For simple scalar models of dark matter, equilibrium can be reached within 10,000 years. For vector models of dark matter, equilibrium can happen in just a year. Regardless of the model, neutron stars can reach thermal equilibrium in a cosmic blink of an eye.

If this model is correct, then dark matter could play a measurable role in the evolution of neutron stars. We could, for example, identify the presence of dark matter by observing neutron stars that are warmer than expected. Or perhaps even distinguish different dark matter models by the overall spectrum of neutron stars.

Reference: Bell, Nicole F., et al. “Thermalization and annihilation of dark matter in neutron stars.” Journal of Cosmology and Astroparticle Physics 2024.04 (2024): 006.

The post Neutron Stars Could be Heating Up From Dark Matter Annihilation appeared first on Universe Today.

After a journey lasting about two billion years, photons from an extremely energetic gamma-ray burst (GRB) struck the sensors on the Neil Gehrels Swift Observatory and the Fermi Gamma-Ray Space Telescope on October 9th, 2022. The GRB lasted seven minutes but was visible for much longer. Even amateur astronomers spotted the powerful burst in visible frequencies.

It was so powerful that it affected Earth’s atmosphere, a remarkable feat for something more than two billion light-years away. It’s the brightest GRB ever observed, and since then, astrophysicists have searched for its source.

NASA says GRBs are the most powerful explosions in the Universe. They were first detected in the late 1960s by American satellites launched to keep an eye on the USSR. The Americans were concerned that the Russians might keep testing atomic weapons despite signing 1963’s Nuclear Test Ban Treaty.

Now, we detect about one GRB daily, and they’re always in distant galaxies. Astrophysicists struggled to explain them, coming up with different hypotheses. There was so much research into them that by the year 2,000, an average of 1.5 articles on GRBs were published in scientific journals daily.

There were many different proposed causes. Some thought that GRBs could be released when comets collided with neutron stars. Others thought they could come from massive stars collapsing to become black holes. In fact, scientists wondered if quasars, supernovae, pulsars, and even globular clusters could be the cause of GRBs or associated with them somehow.

GRBs are confounding because their light curves are so complex. No two are identical. But astrophysicists made progress, and they’ve learned a few things. Short-duration GRBs are caused by the merger of two neutron stars or the merger of a neutron star and a black hole. Longer-duration GRBs are caused by a massive star collapsing and forming a black hole.

This sample of 12 GRB light curves shows how no two are the same. Image Credit: NASA

New research in Nature examined the ultra-energetic GRB 221009A, dubbed the “B.O.A.T: Brightest Of All Time,” and found something surprising. When it was initially discovered, scientists said it was caused by a massive star collapsing into a black hole. The new research doesn’t contradict that. But it presents a new mystery: why are there no heavy elements in the newly uncovered supernova?

The research is “JWST detection of a supernova associated with GRB 221009A without an r-process signature.” The lead author is Peter Blanchard, a Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) postdoctoral fellow.

“The GRB was so bright that it obscured any potential supernova signature in the first weeks and months after the burst,” Blanchard said. “At these times, the so-called afterglow of the GRB was like the headlights of a car coming straight at you, preventing you from seeing the car itself. So, we had to wait for it to fade significantly to give us a chance of seeing the supernova.”

“When we confirmed that the GRB was generated by the collapse of a massive star, that gave us the opportunity to test a hypothesis for how some of the heaviest elements in the universe are formed,” said lead author Blanchard. “We did not see signatures of these heavy elements, suggesting that extremely energetic GRBs like the B.O.A.T. do not produce these elements. That doesn’t mean that all GRBs do not produce them, but it’s a key piece of information as we continue to understand where these heavy elements come from. Future observations with JWST will determine if the B.O.A.T.’s ‘normal’ cousins produce these elements.”

Scientists know that supernova explosions forge heavy elements. They’re an important source of elements from oxygen (atomic number 8) to rubidium (atomic number 37) in the interstellar medium. They also produce heavier elements than that. Heavy elements are necessary to form rocky planets like Earth and for life itself. But it’s important to note that astrophysicists don’t completely understand how heavy elements are produced.

This periodic table from the NASA Scientific Visualization Studio shows where the elements come from, though scientists still have some uncertainty. Image Credit: NASA’s Goddard Space Flight Center

Scientists naturally wondered if an extremely luminous GRB like GRB 221009A would produce even more heavy elements. But that’s not what they found.

“This event is particularly exciting because some had hypothesized that a luminous gamma-ray burst like the B.O.A.T. could make a lot of heavy elements like gold and platinum,” said second author Ashley Villar of Harvard University and the Center for Astrophysics | Harvard & Smithsonian. “If they were correct, the B.O.A.T. should have been a goldmine. It is really striking that we didn’t see any evidence for these heavy elements.”

Stars forge heavy elements by nucleosynthesis. Three processes are responsible for that: the p-process, the s-process and the r-process (proton capture process, slow neutron capture process, and the rapid neutron capture process.) The r-process captures neutrons faster than the s-process and is responsible for about half of the elements heavier than iron. The r-process is also responsible for the most stable isotopes of these heavy elements.

That’s all to illustrate the importance of the r-process in the Universe.

The researchers used the JWST to get to the bottom of GRB 221009A. The GRB was obscured by the Milky Way, but the JWST senses infrared light and saw right through the Milky Way’s gas and dust. The telescope’s NIRSpec (Near Infrared Spectrograph) senses elements like oxygen and calcium, usually found in supernovae. But the signatures weren’t very bright, a surprise considering how bright the supernova was.

“It’s not any brighter than previous supernovae,” lead author Blanchard said. “It looks fairly normal in the context of other supernovae associated with less energetic GRBs. You might expect that the same collapsing star producing a very energetic and bright GRB would also produce a very energetic and bright supernova. But it turns out that’s not the case. We have this extremely luminous GRB, but a normal supernova.”

Confirming the presence of the supernova was a big step to understanding GRB 221009A. But the lack of an r-process signature is still confounding.

Scientists have only confirmed the r-process in the merger of two neutron stars, called a kilonova explosion. But there are too few neutron star mergers to explain the abundance of heavy elements.

This artist’s illustration shows two neutron stars colliding. Known as a “kilonova” event, they’re the only confirmed location of the r-process that forges heavy elements. Credits: Elizabeth Wheatley (STScI)

“There is likely another source,” Blanchard said. “It takes a very long time for binary neutron stars to merge. Two stars in a binary system first have to explode to leave behind neutron stars. Then, it can take billions and billions of years for the two neutron stars to slowly get closer and closer and finally merge. But observations of very old stars indicate that parts of the universe were enriched with heavy metals before most binary neutron stars would have had time to merge. That’s pointing us to an alternative channel.”

Researchers have wondered if luminous supernovae like this can account for the rest. Supernovae have an inner layer where more heavy elements could be synthesized. But that layer is obscured. Only after things calm down is the inner layer visible.

“The exploded material of the star is opaque at early times, so you can only see the outer layers,” Blanchard said. “But once it expands and cools, it becomes transparent. Then you can see the photons coming from the inner layer of the supernova.”

All elements have spectroscopic signatures, and the JWST’s NIRSpec is a very capable instrument. But it couldn’t detect heavier elements, even in the supernova’s inner layer.

“Upon examining the B.O.A.T.’s spectrum, we did not see any signature of heavy elements, suggesting extreme events like GRB 221009A are not primary sources,” lead author Blanshard said. “This is crucial information as we continue to try to pin down where the heaviest elements are formed.”

Scientists are still uncertain about the GRB and its lack of heavy elements. But there’s another feature that might offer a clue: jets.

“A second proposed site of the r-process is in rapidly rotating cores of massive stars that collapse into an accreting black hole, producing similar conditions as the aftermath of a BNS merger,” the authors write in their paper. “Theoretical simulations suggest that accretion disk outflows in these so-called ‘collapsars’ may reach the neutron-rich state required for the r-process to occur.”

The “accretion disk outflows” the researchers refer to are relativistic jets. The narrower the jets are, the brighter and more focused their energy is.

Could they play a role in forging heavy elements?

“It’s like focusing a flashlight’s beam into a narrow column, as opposed to a broad beam that washes across a whole wall,” Laskar said. “In fact, this was one of the narrowest jets seen for a gamma-ray burst so far, which gives us a hint as to why the afterglow appeared as bright as it did. There may be other factors responsible as well, a question that researchers will be studying for years to come.”

The researchers also used NIRSpec to gather a spectrum from the GRB’s host galaxy. It has the lowest metallicity of any galaxy known to host a GRB. Could that be a factor?

“This is one of the lowest metallicity environments of any LGRB, which is a class of objects that prefer low-metallicity galaxies, and it is, to our knowledge, the lowest metallicity environment of a GRB-SN to date,” the authors write in their research. “This may suggest that very low metallicity is required to produce a very energetic GRB.”

The host galaxy is also actively forming stars. Is that another clue?

“The spectrum shows signs of star formation, hinting that the birth environment of the original star may be different than previous events,” Blanshard said.

Yijia Li is a graduate student at Penn State and a co-author of the paper. “This is another unique aspect of the B.O.A.T. that may help explain its properties,” Li said. “The energy released in the B.O.A.T. was completely off the charts, one of the most energetic events humans have ever seen. The fact that it also appears to be born out of near-primordial gas may be an important clue to understanding its superlative properties.”

This is another case where solving one mystery leads to another unanswered one. The JWST was launched to answer some of our foundational questions about the Universe. By confirming that a supernova is behind the most powerful GRB ever detected, it’s done part of its job.

But it also found another mystery and has left us hanging again.

The JWST is working as intended.

The post The Brightest Gamma Ray Burst Ever Seen Came from a Collapsing Star appeared first on Universe Today.

It’s an exciting time for the fields of astronomy, astrophysics, and cosmology. Thanks to cutting-edge observatories, instruments, and new techniques, scientists are getting closer to experimentally verifying theories that remain largely untested. These theories address some of the most pressing questions scientists have about the Universe and the physical laws governing it – like the nature of gravity, Dark Matter, and Dark Energy. For decades, scientists have postulated that either there is additional physics at work or that our predominant cosmological model needs to be revised.

While the investigation into the existence and nature of Dark Matter and Dark Energy is ongoing, there are also attempts to resolve these mysteries with the possible existence of new physics. In a recent paper, a team of NASA researchers proposed how spacecraft could search for evidence of additional physical within our Solar Systems. This search, they argue, would be assisted by the spacecraft flying in a tetrahedral formation and using interferometers. Such a mission could help resolve a cosmological mystery that has eluded scientists for over half a century.

The proposal is the work of Slava G. Turyshev, an adjunct professor of physics and astronomy at the University of California Los Angeles (UCLA) and research scientist with NASA’s Jet Propulsion Laboratory. He was joined by Sheng-wey Chiow, an experimental physicist at NASA JPL, and Nan Yu, an adjunct professor at the University of South Carolina and a senior research scientist at NASA JPL. Their research paper recently appeared online and has been accepted for publication in Physical Review D.

A new study shows how measuring the Sun’s gravitational field could search for additional physics. Credit: NASA/ESA

Turyshev’s experience includes being a Gravity Recovery And Interior Laboratory (GRAIL) mission science team member. In previous work, Turyshev and his colleagues have investigated how a mission to the Sun’s solar gravitational lens (SGL) could revolutionize astronomy. The concept paper was awarded a Phase III grant in 2020 by NASA’s Innovative Advanced Concepts (NIAC) program. In a previous study, he and SETI astronomer Claudio Maccone also considered how advanced civilizations could use SGLs to transmit power from one solar system to the next.

To summarize, gravitational lensing is a phenomenon where gravitational fields alter the curvature of spacetime in their vicinity. This effect was originally predicted by Einstein in 1916 and was used by Arthur Eddington in 1919 to confirm his General Relativity (GR). However, between the 1960s and 1990s, observations of the rotational curves of galaxies and the expansion of the Universe gave rise to new theories regarding the nature of gravity over larger cosmic scales. On the one hand, scientists postulated the existence of Dark Matter and Dark Energy to reconcile their observations with GR.

On the other hand, scientists have advanced alternate theories of gravity (such as Modified Newtonian Dynamics (MOND), Modified Gravity (MOG), etc.). Meanwhile, others have suggested there may be additional physics in the cosmos that we are not yet aware of. As Turyshev told Universe Today via email:

“We are eager to explore questions surrounding the mysteries of dark energy and dark matter. Despite their discovery in the last century, their underlying causes remain elusive. Should these ‘anomalies’ stem from new physics—phenomena yet to be observed in ground-based laboratories or particle accelerators—it’s possible that this novel force could manifest on a solar system scale.”

Artist’s impression of a proposed Solar Gravity Lens telescope. Credit: The Aerospace Corporation

For their latest study, Turyshev and his colleagues investigated how a series of spacecraft flying in a tetrahedral formation could investigate the Sun’s gravitational field. These investigations, said Turyshev, would search for deviations from the predictions of general relativity at the Solar System scale, something that has not been possible to date:

“These deviations are hypothesized to manifest as nonzero elements in the gravity gradient tensor (GGT), fundamentally akin to a solution of the Poisson equation. Due to their minuscule nature, detecting these deviations demands precision far surpassing current capabilities—by at least five orders of magnitude. At such a heightened level of accuracy, numerous well-known effects will introduce significant noise. The strategy involves conducting differential measurements to negate the impact of known forces, thereby revealing the subtle, yet nonzero, contributions to the GGT.”

The mission, said Turyshev, would employ local measurement techniques that rely on a series of interferometers. This includes interferometric laser ranging, a technique demonstrated by the Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission, a spacecraft pair that relies on laser range finding to track Earth’s oceans, glaciers, rivers, and surface water. The same technique will also be used to investigate gravitational waves by the proposed space-based Laser Interferometry Space Antenna (LISA).

The spacecraft will also be equipped with atom interferometers, which use the wave character of atoms to measure the difference in phase between atomic matter waves along different paths. This technique will allow the spacecraft to detect the presence of non-gravitational noise (thruster activity, solar radiation pressure, thermal recoil forces, etc.) and negate them to the necessary degree. Meanwhile, flying in a tetrahedral formation will optimize the spacecraft’s ability to compare measurements.

“Laser ranging will offer us highly accurate data on the distances and relative velocities between spacecraft,” said Turyshev. “Furthermore, its exceptional precision will allow us to measure the rotation of a tetrahedron formation relative to an inertial reference frame (via Sagnac observables), a task unachievable by any other means. Consequently, this will establish a tetrahedral formation leveraging a suite of local measurements.”

Artist’s impression of the path of the star S2 as it passes very close to the supermassive black hole at the center of the Milky Way. Credit: ESO/M. Kornmesser

Ultimately, this mission will test GR on the smallest of scales, which has been sorely lacking to date. While scientists continue to probe the effect of gravitational fields on spacetime, these have been largely confined to using galaxies and galaxy clusters as lenses. Other instances include observations of compact objects (like white dwarf stars) and supermassive black holes (SMBH) like Sagittarius A* – which resides at the center of the Milky Way.

“We aim to enhance the precision of testing GR and alternative gravitational theories by more than five orders of magnitude. Beyond this primary objective, our mission has additional scientific goals, which we will detail in our subsequent paper. These include testing GR and other gravitational theories, detecting gravitational waves in the micro-Hertz range—a spectrum not reachable by existing or envisioned instruments— and exploring aspects of the solar system, such as the hypothetical Planet 9, among other endeavors.”

Further Reading: Physical Review D

The post Formation-Flying Spacecraft Could Probe the Solar System for New Physics appeared first on Universe Today.

Most satellites share the same fate at the end of their lives. Their orbits decay, and eventually, they plunge through the atmosphere toward Earth. Most satellites are destroyed during their rapid descent, but not always

Heavy pieces of the satellite, like reaction wheels, can survive and strike the Earth. Engineers are trying to change that.

Satellite debris can strike Earth and is a potential hazard, though the chances of debris striking anything other than ocean or barren land are low. Expired satellites usually just re-enter the atmosphere and burn up. But there are a lot of satellites, and their number keeps growing.

In February 2024, the ESA’s European Remote Sensing 2 (ERS2) satellite fell to Earth. The ESA tracked the satellite and concluded that it posed no problem. “The odds of a piece of satellite falling on someone’s head is estimated at one in a billion,” ESA space debris system engineer Benjamin Bastida Virgili said.

That would be fine if ERS 2 was an isolated incident. But, according to the ESA, an object about as massive as ERS 2 reenters Earth’s atmosphere every one to two weeks. The statistics may show there’s no threat to people, but statistics are great until you’re one of them.

The ESA’s ERS-2 Earth observation satellite was destroyed when it re-entered Earth’s atmosphere on February 21st, 2004. Heavy parts of satellites, like reaction wheels, don’t always burn up in the atmosphere and can pose a hazard. ESA engineers are working on reaction wheels that will break into pieces to reduce the hazard. Image Credit: Fraunhofer FHR

The risk of being struck by chunks of a satellite isn’t zero. In 1997, a piece of mesh from a Delta II rocket struck someone’s shoulder in Oklahoma. It was a light piece of debris, so the person was okay. But it was an instructive event.

The heaviest parts of satellites, like reaction wheels, can be hazardous because they may not be destroyed during re-entry. Reaction wheels provide three-axis control for satellites without the need for rockets. They give satellites fine pointing accuracy and are useful for rotating satellites in very small amounts.

Reaction wheels can be quite massive. The Hubble Space Telescope has four reaction wheels weighing 45 kg (100 lbs) each. Other satellites don’t have such massive wheels, but the Hubble’s hefty wheels indicate the extent of the hazard. ESA engineers are designing reaction wheels that will break up during re-entry to reduce the hazard of one striking Earth.

“… the need is becoming urgent as more and more satellites are placed in space.”

Kobyé Bodjona, Mechanisms Engineer at the ESA

As part of the design process, they’re testing their wheels in a plasma wind tunnel at the University of Stuttgart Institute of Space Systems. The heated plasma in the tunnel moves at several km/sec, mimicking the friction a satellite is exposed to when it plunges through Earth’s atmosphere. The wheel is rotated inside the tunnel as if tumbling through the atmosphere.

At a recent Space Mechanisms Workshop at ESA’s ESTEC technical center in the Netherlands, engineers showed a clip of the blow-torch effect that the atmosphere has on falling debris.

“Space mechanisms cover everything that enables movement aboard a satellite, from deployment devices to reaction wheels,” explains workshop co-organizer Geert Smet.

“But these mechanisms often use materials such as steel or titanium that are more likely to survive reentry into the atmosphere. This is a problem because our current regulations say reentering satellites should present less than one in 10,000 risks of harming people or property on the ground or even one in 100 000 for large satellite constellations. ESA’s Clean Space group is reacting by D4D—devising methods to make total disintegration of a mission more likely, including mechanisms.”

The effort to make satellites disintegrate completely goes back a few years. The ESA program Design for Demise (D4D) is helping satellite manufacturers comply with the Space Debris Mitigation (SDM) requirements. It’s aimed at eliminating debris falling to Earth, removing debris already in orbit, and designing satellites that don’t linger in orbit after their missions have ended.

At the recent workshop, the ESA revealed more of its plans for active debris removal. There’s a push to develop dedicated spacecraft that can attach themselves to derelict satellites and force them into reentry. This will help remove dead satellites from the congested Low Earth Orbit.

“The idea behind this event is to present the mechanisms community with the latest research on space debris to see how they might contribute to the work going on,” said Kobyé Bodjona, Mechanisms Engineer at the ESA. “It’s important because large system integrators—the big companies that lead satellite projects—are going to need systems that are fully compliant with debris mitigation regulations. And the need is becoming urgent as more and more satellites are placed in space.”

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