Universe Today

How can we explore Saturn’s moon, Enceladus, to include its surface and subsurface ocean, with the goal of potentially discovering life as we know it? This is what a recent study presented at the American Geophysical Union (AGU) 2024 Fall Meeting hopes to address as a team of students and researchers proposed the Thermal Investigation of Geothermal Regions of Enceladus (TIGRE) mission concept, which is designed to conduct in-depth exploration of Enceladus with an orbiter, lander, and drill, while laying the groundwork for future missions to icy moons throughout the solar system.

Here, Universe Today discusses this incredible mission concept with Prabhleen Kour, who is a senior at River Valley High School in Yuba City, CA, and lead author of the study, regarding the motivation behind TIGRE, how TIGRE can improve upon findings from NASA’s now-retired Cassini mission, potential landing sites on Enceladus, how TIGRE can improve missions to other icy moons, the next steps in making TIGRE a reality, and whether she thinks Enceladus has life. Therefore, what was the motivation behind TIGRE?

“TIGRE mission was born during our time with the NASA STEM Enhancement in Earth Science (SEES) program in collaboration with UT Austin’s Center for Space Research,” Kour tells Universe Today. “As part of our internship, our team was tasked to design a space mission within our solar system based on a few assigned parameters. The designed mission had to be aligned to current work being performed by NASA but separate from active missions such as the Europa Clipper. Similarly, the main subject of our mission, Enceladus, and our goals with it, had to be chosen in accordance with the Decadal Survey which dictates what missions and priorities space agencies have. In our case, we were driven to explore a celestial body that might hold the signs of life.”

The TIGRE mission concept comes more than seven years after NASA’s Cassini-Huygen mission ended by performing an intentional dive into Saturn, resulting in Cassini breaking apart in Saturn’s atmosphere. During its storied mission, Cassini spent more than 13 years conducting the most in-depth exploration of Saturn and its many moons, including Titan, Mimas, Atlas, Daphnis, Pandora, Iapetus, Rhea, Dione, Pan, Hyperion, and Enceladus.

Of these moons, Titan and Enceladus are the only two that exhibit potential conditions for life, as Titan is the only moon in the solar system with a dense atmosphere and contains lakes of liquid methane and ethane, while Enceladus boasts a large subsurface ocean that discharge geysers of liquid water from its large crevices in its south pole, dubbed Tiger Stripes. It is the geysers of Enceladus that Cassini not only discovered but flew through twice during its mission, identifying water, carbon dioxide, and a myriad of hydrocarbons and organic materials, the last of which exhibited density 20 times greater than predicted. Therefore, how does TIGRE improve upon findings from the Cassini mission?

Image of Enceladus’ south pole geysers obtained by NASA’s Cassini spacecraft in June 2009. (Credit: NASA/JPL/Space Science Institute)

“Though Cassini’s flyby was incredible and provided us with great information, TIGRE aims to get an incredibly close look at Enceladus’ secrets,” Kour tells Universe Today. “Since TIGRE is designed to go on the surface of Enceladus, it will get more of the ‘inside scoop’ than Cassini. Cassini has already helped us by identifying the organic molecules contained within the ocean, now we want to explore other factors that might make life possible on Enceladus. We are planning to locate any potential regions of interest and stability of habitable zones, analyze samples for organic/inorganic indicators of prebiotic lifeforms, and utilize our findings for future missions. The TIGRE mission contains a drill design, which will reach the subsurface ocean and collect water samples for elements such as CHONPS.”

Enceladus’ Tiger Stripes consist of four main features officially named Damascus Sulcus, Baghdad Sulcus, Cairo Sulcus, and Alexandria Sulcus, with a smaller feature branching off Alexandria called Camphor Sulcus (sulcus being plural for sulci and is an astrogeology term meaning parallel ridges), and are responsible for the geysers that discharge Enceladus’ interior ocean into space. The thickness of the ice in this region is estimated to be approximately 5 kilometers (3.1 miles). Since one of the primary goals of the TIGRE mission is to obtain drill samples of the ocean and identify potential signs of life, the team targeted the Tiger Stripes as potential landing sites for a craft to land and obtain samples of the ocean.

To accomplish this, the team outlined specific landing site criteria to maximize mission success, including landing on relatively flat terrain near a geyser, but not directly on a geyser, to avoid being damaged by uneven terrain or disrupted during geyser activity. Additionally, they determined a low-elevation region would be substantial to minimize the amount of ice the drill would have to penetrate to obtain samples. In the end, the team chose a primary landing site located near the Baghdad stripe that met their landing criteria, located approximately 6.4 kilometers (4 miles) from a geyser and a surface elevation of approximately 450 meters (1,476 feet), along with potential backup landing sites.

Enceladus’ Tiger Stripes. (Credit: NASA/JPL/Space Science Institute)

“Our decision to land near the Baghdad stripe was due to the following: Flat terrain to prevent lander damage, proximity to a geyser, and low elevation to minimize drilling distance,” Kour tells Universe Today. “Any other location that met these requirements were deemed as backups. We analyzed multiple different locations throughout the four stripes, and there were a few that met the requirements on the Cairo stripe. More specifically, one location of interest was between a large geyser and a smaller geyser on the Cario stripe. However, because the location on the Baghdad stripe was close to multiple other smaller geysers, we chose the Baghdad location.”

As noted, Enceladus isn’t the only moon of Saturn that is deemed to potentially have life, as its largest moon, Titan, has a dense and hazy atmosphere caused by specific chemical reactions that scientists have hypothesized existed on early Earth. Additionally, its lakes of liquid methane and ethane have also become prime targets for astrobiologists. Outside of the Saturn system, other icy moons exist throughout the solar system that potentially once had life or could have life today, including Jupiter’s moons, Europa and Ganymede, with both presenting evidence of subsurface oceans circulating beneath their icy crusts.

Venturing closer to the Sun and inside the main asteroid belt orbits the dwarf planet Ceres, which NASA’s Dawn spacecraft identified frozen salts caused by a process known as cryovolcanism. Current models debate the interior structure of Ceres, but it is hypothesized that it once had liquid water long ago. Finally, venturing to the outer portions of the solar system orbits Neptune’s moon, Triton, which NASA’s Voyager 2 spacecraft identified active geysers on its surface comprised of cryolava lakes. Since one of the primary mission objectives of TIGRE is to improve future missions to icy moons, how will it accomplish this?

“The mission will help advance remote sensing, orbiting, landing, and thermal drilling technologies, setting a precedent for future exploration,” Kour tells Universe Today. “TIGRE consists of three main components: the orbiter, lander, and drill. This design is not limited to Enceladus’ surface alone. Instead, this design can be applicable to many other icy surfaces, including those on Earth like Antarctica and other icy moons. Data from the lander’s sampling devices, thermal drill, and the orbiter’s remote sensing will provide comprehensive insights into the composition and formation of Enceladus’s subsurface ocean. These findings could also inform our understanding of other icy moons, broadening our knowledge of potentially habitable environments in the outer Solar System.”

As Universe Today recently discussed with the VATMOS-SR mission concept, it can take anywhere from years to decades for a space mission to go from a concept to reality, involving a myriad of steps and phases, including design, funding rounds, testing, re-designs, re-testing, until it’s finally built and launched. This is followed by several years of traveling to the destination, arriving, and finally collecting science.

For example, the Cassini-Huygens mission was first proposed in 1982 and wasn’t launched until 1997, during which time it endured several years of studies and swapped between a solo NASA mission or a joint NASA-European Space Agency mission, the latter of which was settled upon. After launching in 1997, Cassini finally arrived at Saturn in July 2004, landing the Huygens probe on Titan in January 2005, and spent until 2017 obtaining treasure troves of images and data about Saturn and its many moons, even discovering a few moons along the way and diving through Enceladus’ plumes. Given the journey that Cassini endured, what are the next steps in making TIGRE a reality?

“One of the first steps in making TIGRE a reality is waiting for the completion of the Europa Clipper mission,” Kour tells Universe Today. “In waiting for the mission’s completion, we will be able to see what worked and failed to gather useful samples and what failed to navigate space’s harsh environment. In the meantime, we can advocate for the significance of finding life to enlarge NASA’s budget for active missions. This itself would be a step towards launching the TIGRE mission by opening the resources for improving and testing our mission’s main components (the orbiter, lander, and drill) against the extreme cold, ocean waters, and radiation.”

As noted, Enceladus is a prime target for astrobiologists in the search for life beyond Earth due to its vast subsurface ocean circulating beneath its icy shell. As demonstrated here on Earth, liquid water leads to life as we know it, so Enceladus having a liquid water ocean, even a subsurface ocean, is a strong indicator that it could potentially also have life as we know it, too.

The hydrocarbons discovered by Cassini when the spacecraft flew through Enceladus’ plumes included carbon-bearing molecules like formaldehyde, acetylene, propane, and methane, which is evidence for hydrothermal activity occurring on the ocean floor of Enceladus, much like hydrothermal activity exists on the ocean floors of Earth, specifically regarding the water-rock interactions that occur here, as well. Therefore, in Kour’s opinion, does Enceladus have life and what kinds of life does she foresee finding within their potential TIGRE samples?

“It is not a stretch of reason to state Enceladus could harbor life,” Kour tells Universe Today. “As previously mentioned, Enceladus has the components for life through key elements and has the energy activity to make the possibility of life more plausible. Within the depths of its oceans, Enceladus may very well have life. However, we do not want to explicitly state that there is something there, as there are so many factors at play – thin atmosphere, other chemicals that were potentially not detected by Cassini, and environmental conditions. If there is life and it is similar to the one on Earth, we could expect it to be one of close relations to Archaea. The representatives of this domain are quite primitive and unicellular, which aligns with our hypothesis of Enceladus being able to harbor a simple life form. However, it can also survive harsh conditions – such as extreme cold temperatures on the moon and radiation.”

How will TIGRE help scientists better understand Enceladus and potentially other icy moons throughout the solar system in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post Sampling Enceladus’ Subsurface Ocean with TIGRE Mission Concept appeared first on Universe Today.

Have you ever wondered how astronomers manage to map out the Milky Way when it’s so incredibly vast? One of the most powerful tools is something called 21cm radiation.

Hydrogen, the most abundant element in the universe, plays a key role here. When the electrons in hydrogen atoms flip their spin direction, a specific type of electromagnetic radiation is emitted at a wavelength of 21 centimeters.

The Milky Way galaxy is packed with hydrogen atoms, and these atoms are constantly emitting 21cm radiation. The best part is that this radiation can travel long distances through the interstellar dust that often obscures our view of the galaxy in visible light. This makes 21cm radiation an incredibly useful tool for mapping the structure of the Milky Way.

This radiation reveals everything from star-forming gas clouds to the shapes of the galaxy’s spiral arms. Whereas visible light just gets caught up in all the interstellar dust at it tries to traverse the tens of thousands of light-years across the galaxy, 21cm radiation just sails right though.

But mapping the galaxy’s structure is just one part of the story. Astronomers can also learn about the Milky Way’s rotation by studying the redshift and blueshift of the 21cm radiation. When an object in space moves away from us, the wavelength of the light or radiation it emits gets stretched out, making it appear redder (redshift). Conversely, when an object moves toward us, the wavelength gets compressed, making it appear bluer (blueshift).

By analyzing the redshift and blueshift of the 21cm radiation from different parts of the galaxy, astronomers can determine how fast various regions of the Milky Way are rotating. This information helps them build a more comprehensive picture of our galaxy’s dynamics and motion.

The utility of 21cm radiation isn’t limited to the Milky Way alone. Astronomers can use these same techniques to study distant galaxies as well. By examining the neutral hydrogen gas clouds in far-off galaxies, they can estimate the masses of these galaxies. This is because the amount of 21cm radiation emitted is related to the number of hydrogen atoms present, which in turn gives clues about the galaxy’s overall mass.

21cm radiation is a powerful tool in the field of astronomy that allows astronomers to map the structure of our Milky Way galaxy, understand its rotation, and even estimate the masses of distant galaxies. This technique opens a window into the vast and complex universe, helping us unravel the mysteries of the cosmos with every new observation.

So next time you gaze up at the night sky, remember that there’s a whole lot more going on than meets the eye. Thanks to 21cm radiation, we’re able to peel back the layers of the Milky Way and explore the wonders of the universe in ways that were once unimaginable.

The post How Astronomers Make Deep Maps of the Milky Way appeared first on Universe Today.

NASA astronomers have been continuing to monitor the trajectory of asteroid 2024 YR4. The initial calculations suggested a 1.3% probability of an Earth impact event, which temporarily increased to 3.1% as more data came in. However, and with a sigh of relief, recent analysis brings encouraging news: the Earth impact probability has decreased significantly to 0.28%, though calculations now show a 1% chance of lunar impact. Observations will continue with the James Webb Space Telescope so stay tuned. 

Asteroids are rocky, airless worlds that are remnants left over from the formation of our Solar System about 4.6 billion years ago. They range in size from tiny pebbles to massive bodies hundreds of kilometres across. Most asteroids are found in the asteroid belt between the orbits of Mars and Jupiter although some follow paths that bring them closer to Earth.  Occasionally, they can pose a threat to Earth, which is why astronomers and space agencies closely monitor their orbits and develop potential deflection techniques.

Asteroid Ryugu as seen by Japan’s Hayabusa 2 spacecraft, which returned a sample of the ancient asteroid to Earth in 2020. Image Courtesy ISAS/JAXA

Asteroid 2024 YR4 is one such asteroid that has had gripped the nations media over recent weeks. It’s a near-Earth object that was discovered on 27 December 2024, by the Asteroid Terrestrial-impact Last Alert System (ATLAS) in Chile. Initially, it had an estimated 1.3% chance of impact with Earth in 2032, making it one of the highest-risk asteroids ever recorded. However, further observations raised that risk!

Atlas 2 on Mauna Loa

Astronomers use systems like ATLAS to identify near-Earth objects (NEOs) that could pose a potential threat to our planet. It was developed by the University of Hawaii and funded by NASA and consists of a network of telescopes positioned around the world to provide continuous sky surveys. Its primary goal is to detect asteroids before a potential impact, allowing for timely warnings and mitigation efforts. Since its installation, ATLAS has successfully discovered thousands of asteroids, including hazardous ones just like 2024 YR4. 

Understanding the level of threat from asteroids like 2024 YR4 requires time, time and observations. Imagine a game of tennis and the ball is hit, sending it flying over the net. A photographer sat in the crowd grabs a snapshot of the ball as it flies over the net. The picture is a clear, sharp capture of a point in time however analysis of the image can only reveal the exact location of the ball and not its trajectory. It’s the same with asteroids, once they are discovered, a single observation will reveal where it is but a series of observations are required to understand where it’s going. Ok so this is a simplistic view but it shows how important continued observations are to asteroids like 2024 YR4.

Further observations of asteroid 2024 YR4, conducted during the night of 19-20 February have revealed encouraging results. NASA’s planetary defence team have reported that the probability of an Earth impact has decreased to 0.28%. Monitoring will of course continue to refine trajectory predictions, but current calculations indicate a slight increase in the possibility of lunar impact, now estimated at 1%. These percentages are of course tiny and pose no cause for alarm but 2024 YR4 will continue to be observed over the coming months, just to be sure.

Source : Additional Observations Continue to Reduce Chance of Asteroid Impact in 2032

The post NASA Downgrades the Risk of 2024 YR4 to Below 1% appeared first on Universe Today.

Some exoplanets have characteristics totally alien to our Solar System. Hot Jupiters are one such type. They can have orbital periods of less than 10 days and surface temperatures that can climb to well over 4,000 K (3,730 °C or 6,740 °F). Unlike any planets in our system, they’re usually tidally locked.

Astronomers probed the atmosphere of one hot Jupiter and found some strange winds blowing.

The planet is WASP-121 b, also known as Tylos. It is about 860 light-years away from Earth in the constellation Puppis. It has about 1.16 Jupiter masses and a radius about 1.75 times that of Jupiter. It’s extremely close to its main sequence star and completes an orbit every 1.27 days. Tylos is tidally locked to its star, and its dayside temperature is 3,000 Kelvin (2,730 °C or 4,940 °F), qualifying it as an ultra-hot Jupiter.

“It feels like something out of science fiction.”

Julia Seidel, European Southern Observatory

Since its discovery in 2015, Tylos’ atmosphere has been studied many times. Researchers found water in its stratosphere and hints of titanium oxide and vanadium oxide. They’ve also detected iron and chromium, though some subsequent studies failed to replicate some of these findings.

In new research, scientists examined Tylos’ atmosphere in greater detail with the four telescopes that make up the VLT. With help from the VLT’s ESPRESSO instrument, the researchers found powerful winds blowing through the exoplanet’s atmosphere and confirmed the presence of iron and titanium. The results are in two new papers.

“Even the strongest hurricanes in the Solar System seem calm in comparison.”

Julia Seidel, European Southern Observatory

The first paper, “Vertical structure of an exoplanet’s atmospheric jet stream,” was published in Nature. The lead author is Julia Seidel, a researcher at the European Southern Observatory (ESO).

The second is “Titanium chemistry of WASP-121 b with ESPRESSO in 4-UT mode,” which was published in the journal Astronomy and Astrophysics. The lead author is Bibiana Prinoth, a PhD student at Lund University, Sweden, who is also with the European Southern Observatory.

Some of the researchers involved are co-authors of both papers.

“Ultra-hot Jupiters, an extreme class of planets not found in our solar system, provide a unique window into atmospheric processes,” the authors of the Nature paper write. “The extreme temperature contrasts between their day- and night-sides pose a fundamental climate puzzle: how is energy distributed?”

An artist’s impression of Tylos, also known as WASP-121 b. Image Courtesy: NASA, ESA, Q. Changeat et al., M. Zamani (ESA/Hubble)

“This planet’s atmosphere behaves in ways that challenge our understanding of how weather works — not just on Earth, but on all planets. It feels like something out of science fiction,” said Julia Seidel, the lead author of the study published in Nature.

With the power of the VLT and ESPRESSO, the researchers were able to study Tylos’ atmosphere in detail. No other exoplanet atmosphere has ever been studied in such detail and to such depth. The researchers created a 3D map of the atmosphere, revealing distinct layers and winds.

Tylos’ atmosphere is divided into three layers, with iron winds at the bottom, followed by a very fast jet stream of sodium, and finally, an upper layer of hydrogen winds. This kind of climate has never been seen before on any planet. Image Credit: ESO/M. Kornmesser

“What we found was surprising: a jet stream rotates material around the planet’s equator, while a separate flow at lower levels of the atmosphere moves gas from the hot side to the cooler side. This kind of climate has never been seen before on any planet,” said Seidel. The observed jet stream spans half of the planet, gaining speed and violently churning the atmosphere high up in the sky as it crosses the hot side of Tylos. “Even the strongest hurricanes in the Solar System seem calm in comparison,” she adds.

“It’s truly mind-blowing that we’re able to study details like the chemical makeup and weather patterns of a planet at such a vast distance.”

Bibiana Prinoth, Lund University and the European Southern Observatory

The VLT has an interesting design and is billed by the European Southern Observatory as “the world’s most advanced visible-light astronomical observatory.” It has four main units with 8.2-meter primary mirrors and four smaller, movable auxiliary ‘scopes with 1.8-meter primary mirrors. When working together with the ESPRESSO instrument, the VLT operates as a single, powerful telescope. This combined power meant that the VLT gathered ample data during a single transit of Tylos in front of its star.

“The VLT enabled us to probe three different layers of the exoplanet’s atmosphere in one fell swoop,” said study co-author Leonardo A. dos Santos, an assistant astronomer at the Space Telescope Science Institute. The researchers traced the movement of the winds by tracking the movements of different elements: iron, sodium, and hydrogen correspond to the deep, mid, and shallow layers of the atmosphere. “It’s the kind of observation that is very challenging to do with space telescopes, highlighting the importance of ground-based observations of exoplanets,” he adds.

This diagram shows the structure and motion of the atmosphere of the exoplanet Tylos (WASP-121b). The exoplanet is shown from above in this figure, looking at one of its poles. The planet rotates counter-clockwise in such a way that it always shows the same side to its parent star. One side is perpetual day, and the other is perpetual night. The transition between night and day is the “morning side,” while the “evening side” represents the transition between day and night; its morning side is to the right, and its evening side is to the left. Image Credit: ESO/M. Kornmesser

The observations revealed an exoplanet atmosphere with unusual complexity.

When Tylos crosses in front of its host star, known as a transit, atoms in the planet’s atmosphere absorb specific wavelengths of starlight, which was measured with the VLT’s ESPRESSO instrument. With that data, astronomers reconstructed the composition and velocity of different layers in the atmosphere. An iron wind blows in the deepest layer, away from the point of the planet where the star is directly overhead. Above the iron layer is a very fast jet of sodium that moves faster than the planet rotates. The sodium jet accelerates as it moves from the planet’s morning side to its evening side. The upper layer is made of hydrogen, where the wind blows outwards. The hydrogen layer overlaps with the sodium jet below it.

The authors explain that this unusual planet is more than just an oddity. Its unusual characteristics make it a great testbed for Global Circulation Models. “By resolving the vertical structure of atmospheric dynamics, we move beyond integrated global snapshots of the atmosphere, enabling more accurate identification of flow patterns and allowing for a more nuanced comparison to models,” the authors explain.

The study published in Astronomy and Astrophysics is also based on data from the VLT and ESPRESSO. It uncovered more details of Tylos’ atmosphere, including its chemistry. “The transmission spectrum of WASP-121 b has been extensively studied using the cross-correlation technique, resulting in detections and confirmations for various atoms and ions, including H I, Mg I, Ca I, V I, Cr I, Fe I, Ni I, Fe II, Ca II, and K I, Ba II,” the authors write. “We confirm all these detections and additionally report detections for Ti I, Mn I, Co I Sr I, and Sr II.”

“This experience makes me feel like we’re on the verge of uncovering incredible things we can only dream about now.”

Bibiana Prinoth, Lund University and the European Southern Observatory

The researchers found titanium just below the jet stream. This finding is interesting because previous research detected titanium and subsequent research refuted that. “We attribute the capability of detecting Ti I to the superior photon-collecting power enabled by using ESPRESSO in 4-UT mode compared to a single 1-UT transit and to improvements in the application of the cross-correlation technique,” the authors explain.

The cross-correlation technique is a powerful method for studying exoplanet atmospheres. Light from the atmosphere is much fainter than light from the star and can be obscured by the much stronger starlight. The cross-correlation technique helps overcome this by comparing the observed spectrum with the known “template” spectrum of specific molecules and atoms expected to be present in the atmosphere.

This figure shows the two-dimensional cross-correlation function of H I, Li I, Na I, Mg I, K I, Ca I, Ti I, V I, Cr I, Mn I, Fe I, Fe II, Co I, Ni I, Ba II, Sr I and Sr II. The last panel shows the cross-correlation function for the entire atmospheric model. Image Credit: Prinoth et al. 2025.

“It’s truly mind-blowing that we’re able to study details like the chemical makeup and weather patterns of a planet at such a vast distance,” said Bibiana Prinoth, lead author of the Astronomy and Astrophysics paper.

“The 4-UT mode of ESPRESSO, with its effective photon collecting area equivalent to that of a 16-meter class telescope, serves as a valuable test-bed for pushing the limits of S/N on relatively faint targets,” the authors write in their conclusion.

The study of exoplanet atmosphere with ground-based telescopes will soon get a big boost. In 2028, the long-awaited Extremely Large Telescope should begin operations. It will have a 39.3-metre-diameter primary mirror, giving it 250 times more light-gathering area than the Hubble. It will also feature powerful instruments to probe exoplanet atmospheres.

“The present analysis also allows us to anticipate the observational capabilities of the soon-to-be-commissioned ELT, particularly with regard to time-resolved studies of exoplanet atmospheres,” the authors write.

Who knows what further strangeness is waiting to be discovered in exoplanet atmospheres?

“The ELT will be a game-changer for studying exoplanet atmospheres,” said Prinoth. “This experience makes me feel like we’re on the verge of uncovering incredible things we can only dream about now.”

• Press Release: First 3D observations of an exoplanet’s atmosphere
• Research: Vertical structure of an exoplanet’s atmospheric jet stream
• Research: Titanium chemistry of WASP-121 b with ESPRESSO in 4-UT mode

The post Strange Winds Blow Through this Exoplanet’s Atmosphere appeared first on Universe Today.

Stars form in Giant Molecular Clouds (GMCs), vast clouds of mostly hydrogen that can span tens of light years. These stellar nurseries can form thousands of stars. Astronomers know this because they observe these regions in the Milky Way and the Magellanic Clouds and watch as stars take shape.

But the Universe is more than 13 billion years old and has been forming stars for almost that entire time. The early Universe was different in notable ways. Was star formation any different in the early Universe?

One of the main differences between the early Universe and the modern Universe is metallicity. Elements heavier than hydrogen and helium, called metals in astronomy, didn’t exist in the very early Universe. Only after massive stars formed and died did the Universe’s metallicity increase. Metallicity affects many different processes, including star formation. Metals help cool down clouds of gas and dust, allowing them to collapse and form stars.

Scientists know a lot about the star formation process, but there are many outstanding questions. One of them concerns star formation in the early, low-metallicity Universe. How different was the star formation process billions of years ago?

“We can’t go back in time to study star formation in the early universe, but we can observe parts of the universe with environments similar to the early universe.”

Kazuki Tokuda, Kyushu University, Japan

New research in The Astrophysical Journal tackled the question. It’s titled “ALMA 0.1 pc View of Molecular Clouds Associated with High-mass Protostellar Systems in the Small Magellanic Cloud: Are Low-metallicity Clouds Filamentary or Not?” The lead author is Kazuki Tokuda, a Post-doctoral fellow in the Department of Earth and Planetary Sciences in the Faculty of Science at Kyushu University in Japan. Tokuda is also affiliated with the National Astronomical Observatory of Japan.

This simulation shows stars forming in a molecular cloud, including the jets emitted by young protostars. Astrophysicists know a lot about the star-formation process, but there are still many questions awaiting comprehensive answers. Video Credit: Mike Grudic/STARFORGE

“Even today our understanding of star formation is still developing, comprehending how stars formed in the earlier universe is even more challenging,” said lead author Tokuda in a press release. “The early universe was quite different from today, mostly populated by hydrogen and helium. Heavier elements formed later in high-mass stars. We can’t go back in time to study star formation in the early universe, but we can observe parts of the universe with environments similar to the early universe.”

One of those places is the Small Magellanic Cloud (SMC), a dwarf galaxy near the Milky Way. The SMC’s metallicity is much lower than the Milky Way’s, containing only about one-fifth as many metals. This makes it analogous to the early Universe about 10 billion years ago.

In the Milky Way, star-forming molecular clouds tend to have a filamentary structure. Astronomers have wondered whether these same filamentary shapes are a universal feature found throughout cosmic time. “To test whether these structures are universal throughout cosmic star formation history, it is crucial to study low-metallicity environments within the Local Group,” the authors explain in their paper. Since the SMC is a close neighbour and also has a low metallicity, it’s a good place to look. However, searching the SMC for these filamentary features has been difficult due to the insufficient spatial resolution of many observatories.

The researchers used the Atacama Large Millimeter-submillimeter Array’s (ALMA) power to examine the SMC and see if it has the same star-forming filamentary structures. They focused on the molecular clouds associated with massive young stellar objects (YSOs) in the (SMC).

This image from the research shows the overall view of the SMC and the positions of the target YSOs. Image Credit: Tokuda et al. 2025.

“In total, we collected and analyzed data from 17 molecular clouds. Each of these molecular clouds had growing baby stars 20 times the mass of our Sun,” said lead author Tokuda in a press release. “We found that about 60% of the molecular clouds we observed had a filamentary structure with a width of about 0.3 light-years, but the remaining 40% had a ‘fluffy’ shape. Furthermore, the temperature inside the filamentary molecular clouds was higher than that of the fluffy molecular clouds.”

This figure from the new research shows the 17 molecular clouds the researchers observed with ALMA. Most had the same filamentary shape as clouds in the Milky Way, shown in the yellow boxes. But 40% had a fluffy shape, as shown in the blue boxes. Image Credit: (ALMA (ESO/NAOJ/NRAO), Tokuda et al. 2025, ESA/Herschel)

In their paper, the authors describe it this way: “Our analysis shows that about 60% of the clouds have steep radial profiles from the spine of the elongated structures, while the remaining clouds have a smooth distribution and are characterized by lower brightness temperatures. We categorize the former as filaments and the latter as nonfilaments.”

This figure shows the 17 molecular clouds in the study. The ones with yellow check marks are the ones identified as filaments. Image Credit: Tokuda et al. 2025.

The clouds were not uniform and displayed a diversity of shapes. The researchers classified them into four separate types: single filaments, hub filaments, spatially compact clouds, and diffuse clouds.

These panels illustrate the four types of filaments the authors used to categorize their observations: (a) single filaments, (b) hub filaments, (c) spatially compact clouds, and (d) diffuse clouds. Image Credit: Tokuda et al. 2025.

The temperature difference between the filamentary and fluffy shapes was probably due to their ages. The authors think all clouds started out as filamentary and had high temperatures due to cloud-to-cloud collisions. The clouds have weak turbulence when the temperatures are higher.

However, as the temperature drops, the movement of the incoming gas creates more turbulence. This smooths out the filamentary structure, creating the fluffy shapes.

According to the research, filamentary and fluffy clouds form stars differently. Clouds that hold onto their filamentary shapes are more likely to break apart along their length and form many lower-mass stars similar to our Sun, including planetary systems. When the filamentary structure changes to a fluffy structure, it becomes more difficult for such stars to form.

The implication is that the morphology of the clouds tells us about their evolutionary stages.

“Some of the filamentary clouds are associated with YSOs with outflows and exhibit higher temperatures, likely reflecting their formation conditions, suggesting that these clouds are younger than the nonfilamentary ones,” the authors write in their paper.

The study also emphasizes that the same temperature and structure changes have not been observed in higher metallicity environments like the Milky Way. “Such transitions in structure and temperature have not been reported in metal-rich regions, highlighting a key behaviour for characterizing the evolution of the interstellar medium and star formation in low-metallicity environments,” the authors explain.

With these results, Tokuda says the next step will be to compare them with observations of the Milky Way and other environments richer in heavy elements.

“This study indicates that the environment, such as an adequate supply of heavy elements, is crucial for maintaining a filamentary structure and may play an important role in the formation of planetary systems,” said Tokuda. “In the future, it will be important to compare our results with observations of molecular clouds in heavy-element-rich environments, including the Milky Way galaxy. Such studies should provide new insights into the formation and temporal evolution of molecular clouds and the universe.”

There are still more details to uncover about these filaments, what shapes them, and how they affect the stars they form. How does turbulence play its role? What role do magnetic fields play? Some filaments host YSOs with protostellar outflows. How does that radiative feedback affect the filaments?

Future research will address those questions.

“Future studies using the James Webb Space Telescope to measure the detailed IMF <initial mass function> down to the low-mass regime, combined with ALMA’s ability to probe the physical properties of the parent molecular gas, will be crucial to deepening our understanding of star formation in low-metallicity environments,” the authors conclude.

• Press Release: In ancient stellar nurseries, some stars are born of fluffy clouds
• Research: ALMA 0.1 pc View of Molecular Clouds Associated with High-mass Protostellar Systems in the Small Magellanic Cloud: Are Low-metallicity Clouds Filamentary or Not?

The post Fluffy Molecular Clouds Formed Stars in the Early Universe appeared first on Universe Today.

Let’s dive into one of those cosmic curiosities that’s bound to blow your mind: how we might chat with aliens. And no, I’m not talking about elaborate coded messages or flashy signals. We’re talking about something incredibly fundamental—21cm radiation.

If you’re planning on having a conversation across the vastness of space, using light waves (electromagnetic radiation) is pretty much your go-to option. It’s fast, reliable, and, well, it’s the most practical way to shout out to other civilizations in the universe. But why specifically 21 centimeters? That’s where things get juicy.

This 21cm radiation isn’t just some random frequency we picked out of a hat. It’s tied to something very essential, known as the hydrogen spin flip. Hydrogen atoms consist of one proton and one electron, and these tiny particles have a property called “spin.” Think of spin like a little arrow pointing up or down. Every so often, in the vast reaches of space, a hydrogen atom’s electron can flip its spin, going from a state where its spin is aligned with the proton to one pointing in the opposite direction. This flip releases energy in the form of radiation at—you guessed it—a wavelength of 21 centimeters.

So, why does this matter? Well, any smart civilization, whether they have blue skin, tentacles, or something more bizarre, will eventually discover hydrogen, understand spin, dabble in quantum mechanics, and figure out this whole 21cm radiation thing. They’ll call it something different (they won’t have “21” or “cm”) but the concept remains universal. It’s like the cosmic Rosetta Stone.

What makes 21cm radiation perfect for long-distance interstellar chats is its ability to cut through interstellar dust. Space is filthy, with dust clouds that block out other forms of light. However, 21cm waves are like the VIPs of the universe, slipping through the velvet ropes of cosmic debris to carry their message far and wide.

Here’s a fun fact: NASA’s Pioneer spacecraft, launched in the early 1970’s, carry plaques. On these plaques there’s a handy diagram of the hydrogen spin flip transition. All other measurements on the plaque, including the height of humans, are made in reference to this fundamental distance. So the hope is that aliens can recognize the hydrogen spin-flip transition and use that to unlock the rest of our message.

Now imagine this scenario: One day, astronomers on Earth detect an unusual surge of 21cm radiation. It’s not coming from a random hydrogen cloud; it’s directional, purposeful. That could very well be an alien civilization sending us a “What’s up?” across the cosmos – 21cm radiation makes for a great calling card.

Using 21cm radiation to communicate with extraterrestrial beings leverages a basic, universal constant. And who knows? Maybe one day, when we finally hear that signal, we’ll know that somewhere out there, another intelligent species figured out the same galactic hack we did.

So keep your eyes—or rather, your telescopes—peeled. The next big discovery could be just a spin flip away!

The post If You’re Going to Call Aliens, Use This Number appeared first on Universe Today.

The majority of the universe remains unmapped, but we have a potential window into it through a peculiar light emitted by nothing other than neutral hydrogen.

Before stars and galaxies lit up the universe, the cosmos was a dark place filled mostly with neutral hydrogen. This was right after the Big Bang and the formation of the CMB—Cosmic Microwave Background. The CMB is like a baby picture of the universe when it was just 380,000 years old. But what came next was a long period called the “Dark Ages.” During this time, the universe didn’t have much going on in terms of visible light because there were no stars or galaxies yet. Frustratingly, most of the volume of the visible universe exists in these Dark Ages, which makes it a very valuable resource to learn about the nature of dark matter and dark energy. But…it was dark, so we can’t just make a bigger telescope and observe it.

Thankfully, the neutral hydrogen that filled the universe during this epoch does emit a feeble kind of light. Due to the quantum mechanical spin flip transition, neutral hydrogen emits radiations with a wavelength of 21 centimeters. However, the Dark Ages were so long ago at this 21cm radiation is redshifted to a wavelength of two meters or more, putting it firmly in the radio band of the electromagnetic spectrum.

In fact, a tiny fraction of the static you hear in your car radio is due to this ancient radiation.

Astronomers can use slightly different wavelengths to map out the extent and evolution of the Dark Ages. Different pockets of neutral gas will emit their radiation at different times, which will correspond to different redshifts.

We expect to see an enormous amount of 21cm radiation at the very longest wavelengths, right at the beginning of the Dark Ages. That’s when the universe was filled with an almost uniform distribution of neutral hydrogen. Then as the first stars and galaxies wake up, they ionize their surrounding gas with powerful blasts of high-energy radiation. So a 21cm map of this era should show holes and pockets in the overall signal. Finally, once most of the neutral hydrogen is wiped away and confined only to cool regions of galaxies, we should see the signal disappear – only to be replaced with the light of galaxies themselves.

However, observing this radiation is a daunting task. That’s because humans are also quite fond of radio emissions, and this signal from the Dark Ages is at least a million times weaker than terrestrial radio broadcasts. Observatories around the world, like the Murchison Wide-field Array in Western Australia and the Hydrogen Epoch of Reionization Array in South Africa have so far failed to find a conclusive signal.

To nail this detection and open up the Dark Ages to exploration, we may have to go off planet. The Lunar Crater Radio Telescope hopes to turn the far side of the Moon into a pristine radio observatory, using the Moon itself to shield the observatory from radio interference. The idea is a long way off, but it might be our only way to to draw a complete map of the cosmos’ past, present, and future.

The post Neutral Hydrogen: The Next Big Game in Cosmology appeared first on Universe Today.

NASA engineers are pressing ahead with preparations for the Artemis II mission unless someone tells them otherwise. The ambitious flight will send four astronauts on a trajectory similar to Apollo 8’s historic lunar journey, with the crew traveling around the Moon in an Orion Capsule before returning to Earth. A crucial milestone in the mission preparations was reached as technicians completed the assembly of the Space Launch System’s twin solid rocket boosters inside the Vehicle Assembly Building. The stacking process began in late November 2024 and concluded on February 19th.

In a significant step forward for our return to the Moon, NASA engineers at Kennedy Space Center have finished assembling the massive solid rocket boosters that will power the Artemis II mission. The stacking operation, completed on 19 February 2025, marks a key milestone in preparation for the first crewed lunar mission since Apollo. As someone who never saw the Apollo Moon landings, I’m excited. 

Aldrin on the Moon. Astronaut Buzz Aldrin walks on the surface of the moon near the leg of the lunar module Eagle during the Apollo 11 mission. Mission commander Neil Armstrong took this photograph with a 70mm lunar surface camera. While astronauts Armstrong and Aldrin explored the Sea of Tranquility region of the moon, astronaut Michael Collins remained with the command and service modules in lunar orbit. Image Credit: NASA

The assembly process began on 20 November 2024, inside Kennedy’s amazing Vehicle Assembly Building (VAB), where generations of Moon rockets have been built. Using techniques that have been refined over decades of spaceflight experience, technicians employed one of the facility’s overhead cranes to carefully position each segment of the twin boosters.

These solid rocket boosters represent modern engineering at its best, being assembled on Mobile Launcher 1, a huge structure standing 380 feet tall – roughly the height of a 38-story building. This launch platform serves a number of different functions, acting as both the assembly base for the Space Launch System (SLS) rocket and Orion spacecraft, and the launch platform from which the mission will eventually depart for the Moon.

NASA’s Space Launch System (SLS) rocket with the Orion spacecraft aboard is seen at sunset atop the mobile launcher at Launch Pad 39B as preparations for launch continue, Wednesday, Aug. 31, 2022, at NASA’s Kennedy Space Center in Florida. Credit: (NASA/Joel Kowsky)

The completed boosters will form part of the most powerful rocket ever built by NASA, more powerful even than Saturn V that took Apollo astronauts to the Moon. When ignited, these twin rockets will generate millions of pounds of thrust, working in together with the SLS core stage to lift the Orion spacecraft and its four-person crew toward the Moon.

Apollo 11 launch using the Saturn V rocket

Artemis II represents a historic moment in space exploration as the first time humans will venture beyond low Earth orbit since 1972. The mission profile calls for a crew of four astronauts to journey around the Moon in the Orion spacecraft, testing critical systems and procedures before future missions attempt lunar landings.

The successful completion of booster stacking demonstrates the expertise of NASA’s engineering teams. Each segment had to be perfectly aligned and secured, with no room for error in a process that demands accuracy. The boosters will eventually help propel the spacecraft to speeds exceeding 17,000 miles per hour – fast enough to break free of Earth’s gravity and get to the Moon.

With this milestone achieved, NASA continues toward launch, carefully checking and testing each system to ensure the safety of the crew and the success of this ambitious mission to return humans to deep space.

Moon, here we come, once again. 

Source : Artemis II Rocket Booster Stacking Complete

The post The Artemis II Boosters are Stacked appeared first on Universe Today.

It’s not uncommon for space missions to be tested here on planet Earth. With the plethora of missions that have been sent to Mars it  is becoming increasingly likely that the red planet was once warmer, wetter and more habitable than it is today. To find evidence of this, a new paper proposes that Deception Island in Antarctica is one of the best places on Earth to simulate the Martian environment. The paper identifies 30 sites on the island that correspond well to places on Mars.

The exploration of Mars has been a focus of space agencies worldwide, driven by the desire to understand the its geology, climate, possibility of past life, and excitingly the potential for future human colonisation. Early missions, such as NASA’s Mariner 4 in 1965, provided the first close-up images of Mars, while the Viking landers of the 1970s conducted the first successful surface experiments. In the 1990s and 2000s, orbiters like Mars Global Surveyor and rovers like Spirit and Opportunity helped us to understand more about the Martian terrain and atmospheric conditions. As we explore the red planet, and with more projects on the horizon, Mars remains a key target for exploration. 

Three Generations of Mars Rovers in the ‘Mars Yard’ at the Jet Propulsion Laboratory. The Mars Pathfinder Project (front) landed the first Mars rover – Sojourner – in 1997. The Mars Exploration Rover Project (left) landed Spirit and Opportunity on Mars in 2004. The Mars Science Laboratory Curiosity rover landed on Mars in August 2012. Credit: NASA/JPL-Caltech.

The world that has been revealed following the multitude of missions is of a surface that is cold, dry, and exposed to high radiation. Evidence exists that liquid water once flowed on Mars, bringing the tantalising possibility that microbial life may have existed in the past. Today, underground water reserves and seasonal methane emissions hint at the possibility of present-day life BUT and it is a strong BUT, no evidence has been found yet.   Further exploration is required and it is at times like this that researchers turn to planetary analogues to explore further. 

Image taken by the Viking 1 orbiter in June 1976, showing Mars thin atmosphere and dusty, red surface. Credits: NASA/Viking 1

A planetary analogue is a location on Earth that is similar or identical to places found on alien worlds. In the case of Mars, a new paper has been published that suggests that Deception Island in Antarctica is a great ‘analogue’ for parts of Mars. Exploring life that is found in these locations enables us to better understand the locations on Mars and helps inform future exploration. 

The paper, that was authored by a team led by María Angélica Leal Leal identifies 30 locations on the island that are an excellent match for locations on Mars. The locations have been divided into four categories; geologically similar to areas of Mars, environmental conditions are similar to Mars, biological interest due to the existence of extremophiles on Earth and various engineering applications enabling hardware testing in Mars-like environment. 

It concludes that Deception Island in Antarctica serves as a valuable Mars analogue site due to the combination of extreme environmental conditions and geological features that mirror those found on Mars. It’s a volcanic island too offering a natural (and significantly closer) laboratory where it might reveal how life adapts to harsh conditions including low temperatures and high radiation. 

The island’s particularly unique features include the presence of perchlorate (chemical compounds that contain salts made up of chlorine and oxygen atoms,) glaciovolcanic processes, permafrost, and microbial mats (layers of complex microorganisms) that survive in extreme conditions. This all makes for an excellent terrestrial alternative for studying potential past or present life on Mars. However, the researchers note that further detailed studies of the island’s geochemistry, extremophile organisms, and mission simulations are needed to fully confirm its validity as a Mars analogue for specific Martian regions and time periods.

Source : The potential of Deception Island, Antarctica, as a multifunctional Martian analogue of astrobiological interest

The post Antarctica’s Deception Island is the Perfect Place to Practice Exploring Mars appeared first on Universe Today.

Some of our Solar System’s moons have become very enticing targets in the search for life. There’s growing evidence that some of them have oceans under layers of ice and that these oceans are warm and rich in prebiotic chemistry. NASA’s Europa Clipper is on its way to examine Jupiter’s moon Europa, and the ESA’s Jupiter Icy Moons Explorer is also on its way to the Jovian system to explore some of its icy moons.

While the presence of an ocean on Europa is becoming widely accepted, there’s more uncertainty about the other Galilean moons. However, new evidence suggests that Callisto is very likely an ocean moon, too.

Callisto is Jupiter’s second-largest moon, the third-largest moon in the Solar System, and the outermost Galilean moon. The Voyager probes gave us our first close looks at Callisto in 1979, and the Galileo spacecraft gave us our best images and science data during flybys between 1996 and 2001. Galileo provided the first evidence that Callisto may harbour a subsurface ocean.

Callisto has a different appearance than other suspected ocean moons like Europa and Saturn’s Enceladus. Europa clearly has a white, icy surface, although it has other brownish colours, too. Enceladus has an extremely bright, icy surface and has the highest albedo of any object in the Solar System. Callisto, on the other hand, has a dark, icy surface and is covered in craters.

Europa (L), Enceladus (M), and Callisto (R) have distinctly different surfaces, yet all likely have subsurface oceans.

However, the evidence for its ocean is unrelated to its surface appearance and any visible ice.

The main evidence supporting an ocean on Callisto comes from the moon’s magnetic field. Unlike Earth’s internally generated magnetic field, Callisto’s is induced. That means the field is created from Callisto’s interactions with Jupiter and its extremely powerful magnetic field. For Callisto to induce a magnetic field, it has to have a layer of conductive material.

This illustration shows Jupiter’s powerful magnetic field and the four Galilean moons. Image Credit: ESA.
Licence: ESA Standard Licence

The question is, is the layer an ocean or something else?

Different researchers have been trying to answer that question since Galileo gathered its data. One of the spacecraft’s instruments was a magnetometer, a type called a Dual-Technique Magnetometer (DTM). There are multiple types of magnetometers, and each one works differently. Galileo’s DTM provided redundancy and allowed for cross-checking, which increased the accuracy and reliability of its data. It was especially good at detecting the subtle magnetic fields of Jupiter’s moons, including Callisto. It also collected data continuously, which let scientists gain insights into how the magnetic fields of Jupiter and its moons varied over time due to different interactions.

In a 2017 paper, researchers pointed to the ionosphere as the primary cause of Callisto’s magnetic fields. “We find that induction within Callisto’s ionosphere is responsible for a significant part of the observed magnetic fields,” the authors wrote. “Ionospheric induction creates induced magnetic fields to some extent similar as expected from a subsurface water ocean.”

New research in AGU Advances based on Galileo data strengthens the idea that Callisto has a subsurface ocean and that it’s responsible for the moon’s magnetic field rather than its ionosphere. The paper is titled “Stronger Evidence of a Subsurface Ocean Within Callisto From a Multifrequency Investigation of Its Induced Magnetic Field.” The lead author is Corey Cochrane, a scientist at JPL who studies planetary interiors and geophysics. An important part of this research is that they considered data from multiple Galileo flybys (C03, C09, and C10).

“Although there is high certainty that the induced field measured at Europa is attributed to a global-scale subsurface ocean, there is still uncertainty around the possibility that the induced field measured at Callisto is evidence of an ocean,” Cochrane and his co-researchers write. “This uncertainty is due to the presence of a conductive ionosphere, which will also produce an induction signal in response to Jupiter’s strong time-varying magnetic field.”

Observations acquired from the Galileo spacecraft indicate that Callisto (left) reacts inductively to Jupiter’s (right) time-varying magnetic field. New research suggests that this reaction and its results are indicative of the moon hosting a subsurface salty ocean. Image Credit: Corey J. Cochrane, NASA/JPL-Caltech

In short, Callisto’s magnetic field could be caused by its ionosphere, an ocean, or a combination of both. The problem is that Callisto’s conductive ionosphere creates a magnetic field that can mask the presence of an ocean. To get to the truth, the authors used previously published simulations of the moon’s interactions combined with “both an inverse and an ensemble forward modeling method.” The authors write that this brings some clarity about the possible range of Callisto’s interior properties.

The researchers created a four-layer model of Callisto, including its ionosphere. “Among these models, we vary the thickness of the ice shell, the thickness of the ocean, and the conductivity,” the authors write. They also varied the seafloor depth and the ionosphere’s conductance.

This schematic diagram from the study shows the variable parameters in some of the researchers’ modelling. (Left) D is seafloor depth, T is ocean thickness, and Rc is conductance. (R) The ocean parameter space in the study has 8 linear steps for ocean thickness and 10 steps for ocean conductivity. Image Credit: Cochrane et al. 2025.

The researchers concluded that the moon’s ionosphere alone cannot explain the magnetic field. Instead, it “more likely arises from the combination of a thick conductive ocean and an ionosphere rather than from an ionosphere alone.”

They also concluded that the ocean is tens of kilometres thick from the seafloor to the ice shell, and the ice shell could also be tens of kilometres thick. “As our results demonstrate, both the inverse and forward modelling approaches support the presence of an ocean when considering data acquired from flyby C10 alongside C03 and C09,” the researchers explain. “Our analysis, the first to simultaneously fit C03, C09, and C10 flyby data together, favours the presence of a thick and deep ocean within Callisto.”

The models also favour a thick ice shell “consistent with Callisto’s heavily cratered geology,” they explain.

Galileo wasn’t dedicated to studying Callisto, so there is a dearth of data in all research into its magnetic fields. “It is challenging to place tighter constraints on the properties of Callisto’s ocean because of the limited number of close Galileo flybys that produced reliable data and because of the uncertainty associated with the plasma interaction,” the authors write in their conclusion.

Better and more complete data is in the future, though. Both NASA’s Europa Clipper and the ESA’s JUICE mission will gather more data, some of it from very close to Callisto’s surface.

The Europa Clipper is scheduled to make nine flybys of Callisto. Seven will be within 1800 km of the surface, and four of those will be within 250 km. Its magnetometer will operate continuously during those flybys. The ESA’s JUICE mission is scheduled to perform 21 flybys of Callisto. All of them will be within 7000 km of the surface, and most will be below 1000 km.

The Europa Clipper’s elliptical orbit will allow it to perform flybys of Jupiter’s moons, including Callisto. Image Credit: NASA/JPL-Caltech

Both the Europa Clipper and JUICE have instruments that Galileo didn’t have. Though Galileo came within about 1100 km of Callisto’s surface, it simply could not provide the same kind of data that these newer missions will. The Clipper and JUICE are scheduled to reach the Jovian system in 2030 and 2031, respectively.

As their data starts to arrive and reaches scientists, we will likely determine for sure if Callisto is yet another of the Solar System’s ocean moons.

• Press Release: Jupiter’s Moon Callisto Is Very Likely an Ocean World
• Research: Stronger Evidence of a Subsurface Ocean Within Callisto From a Multifrequency Investigation of Its Induced Magnetic Field

The post Does Jupiter’s Moon Callisto Have an Ocean? The Evidence is Mounting appeared first on Universe Today.

Gateway’s HALO module heads to the U.S., on its long path to orbiting the Moon.

Preparations for Lunar Gateway are starting to come together. Thales Alenia Aerospace engineers recently began a series of checks on the HALO (Habitation Logistics Outpost) core module. Currently at the company’s Turin, Italy facility, the module is set to head to the U.S. to contractor Northrop Grumman’s Gilbert, Arizona site next month, aboard an Antonov AN-124-100 aircraft.

The HALO segment is the crucial core of what will become Lunar Gateway. Along with environmental and stress tests, the Thales Alenia team will install valves, carry out leak checks, and prepare for integrating secondary structures with HALO. One airlock, the Emirates Crew and Science Module was built and provided by the United Arab Emirates’ Mohammed bin Rashid Space Centre. The airlock will be used for space walks outside of Gateway. In exchange, the UAE will receive an astronaut slot on an Artemis expedition.

The first welding of the ring and cylinder segments for HALO occurred at Thales Alenia Space in 2021, marking the first major milestone for assembly of the module’s primary structure.

The HALO core module on the move. Credit: Thales Alenia Space.

Northrop Grumman was awarded the $935 million dollar contract to develop the Gateway HALO module in 2021. NASA’s FY2025 budget allocates over $817 million for the continued construction of Gateway.

Looking inside the HALO module. Credit: Thales Alenia Space. What’s Next for HALO and Gateway

“To ensure all flight hardware is ready to support Artemis IV—the first crewed mission to Gateway—NASA is targeting the launch of HALO and the Power and Propulsion Element no later than December 2027,” Laura Rochon (NASA-Johnson Spaceflight Center) told Universe Today in a recent email. “These modules will launch together aboard a SpaceX Falcon Heavy rocket and spend about a year traveling uncrewed to lunar orbit, while providing scientific data on solar and deep space radiation during transit.”

Once the module arrives at Northrop Grumman’s Arizona facility, it will undergo more tests and integration with the propulsion stage prior to launch. As one of four pressurized modules, HALO will support crew, experiments and internal and external payloads. Gateway will serve as a staging point, supporting lunar research and crews on the surface. One big advantage for Gateway is that it would act as a reusable ‘command module’ for expeditions to the Moon, allowing for longer stays on the surface.

Part of the propulsion element for Gateway. Credit: NASA/JSC/Maxar Space Systems. A Deep Space Station

Like the International Space Station, Gateway is an international effort. The European Space Agency is designing its Lunar Link (part of ESA’s larger LunaNet DTN framework initiative) for the station. The Canadian Space Agency (CSA) is supplying a robotic arm, its Small Orbital Replacement Unit Robotic Interface. Gateway will be approximately a fifth the size and volume of the ISS. Unlike the permanently crewed ISS, Gateway will only host temporary expeditions, and will spend much on its time vacant and running in autonomous mode.

An artist’s conception of Gateway in orbit around the Moon. Credit: NASA-JSC.

“The ISS has been a cornerstone of space research in low-Earth orbit for more than two decades,” says Rochon. “Gateway expands this legacy into the deep space environment. Gateway will operate in orbit around the Moon, where radiation is a greater concern due to lack of a protective shield. It took 40 launches and over 13 years to build the ISS. Gateway will be fully constructed in four launches using advanced technology and capabilities focused on what is needed to support long-term human lunar exploration.”

Science and research will still happen on Gateway… even when humans are absent. “Gateway will focus on pushing the boundaries of remote and autonomous operations,” says Rochon. “This will enable Gateway to conduct science investigation and support missions, even when crew are not present.”

Putting Gateway together. Credit: NASA. Artemis at a Crossroads

This all happens at a time of change and uncertainty for NASA. A layoff of 1,000 employees announced earlier this week was put on hold…for now. Many pundits have also questioned the burgeoning complexity and cost overruns for the Artemis initiative, and if Gateway is still needed.

NASA’s large Space Launch System (SLS) rocket finally got off the ground with Artemis I in November 2022. The first crewed lunar flyby on Artemis II has been pushed back to April 2026. The first lunar landing mission on Artemis III relies heavily on SpaceX’s Starship Heavy and Starship HLS (Human Landing System) as part of its architecture. Starship has another suborbital launch coming up on February 26th. The first possible orbital flight of Starship is planned for this April. SpaceX still has lots of hurdles to overcome prior to the Artemis III lunar landing, set for 2027.

Gateway will orbit the Moon in a unique, Near-rectilinear halo orbit (NRHO). This unique type of orbit is necessary for astronauts to access the entirety of the lunar surface. This is especially true for a landing in the south polar regions. The Cis-Lunar Autonomous Positioning System Technology Operations Navigations Experiment (CAPSTONE) mission launched in 2022 on a Rocket Lab Electron rocket is pioneering this type of orbit. An NRHO path also affords the station a near-continuous line-of-sight communications link with controllers on Earth.

Despite the hurdles it faces, it would be great to finally see humans living and working around the Moon. Imagine the view! For now, we can watch as the pieces come together, and the core HALO module for Gateway takes ‘one small step’ closer to the launch pad.

The post Lunar Gateway’s Core HALO Module Enters the Clean Room appeared first on Universe Today.

What if I told you there was a secret window, and if you looked through this window you could see the entire history of the universe unfold before your very eyes?

It sounds too good to be true. But this is science, and if we’ve learned anything in our four centuries of scientific exploration of nature, its that science can produce miracles. Or in this case, science can take advantage of nature’s own miracles.

I’m talking about a curious little feature of the humble hydrogen atom. One proton, one electron. Done, the simplest atom possible. You can throw a neutron in there if you’re feeling generous. It’s not necessary but adds a little bit of fiber.

Now this proton and this electron are particles, which means they have a list of properties, like mass and charge. Those properties tell us how the particles respond to the gravitational force and the electric force. And then there’s this other property, a property we call spin. When I say “spin” everybody, including myself, thinks of the obvious: something spinning, like a Harlem globetrotter spinning a basketball on their pinky finger. But these are particles, which means they take up no volume in space, so how do they…spin?

The answer is they don’t. But they kind of do. It’s really weird and complicated and it’s one of those many quantum things that we just have to learn to live with, because there’s no getting around it and quantum mechanics doesn’t really care if we understand it or not. The spin of a particle refers to, essentially, how it responds to magnetic fields. If you were to take a metal ball and charge it up with electricity, and then set it spinning and throw it into a magnetic field, there’s a natural response of that spinning metal charged ball to the magnetic field. If it’s spinning one way, the ball gets deflected in one direction. If it’s spinning the other way, it goes the other way.

Particles like electrons and protons do that: they respond to magnetic fields exactly as if they were charged metal balls. They’re not, but they still act like they are, so we call it spin because that’s the closest thing we can call this, and we have to move on.

And particles like protons and electrons can have one of two choices for their spin. We call these choices up and down, because when we shoot these particles through a magnetic field that points up-and-down, the up-pointing particles go up and the down-spinning particles go down. We could have called these spin states left and right or a and b or alice and bob, but we went with up and down.

In a hydrogen atom, the electron and proton can either have the same direction of spin (both up or both down) or they can have opposite spins. For various quantum mechanical reasons having to do with overlap of the wavefunctions, when the proton and electron have the exact same spin, that configuration has ever so slightly more energy than the situation than when they’re the opposite.

That means that when they find themselves in that same-spin situation, because quantum mechanics allows all sorts of randomness like that, they can realign themselves to reach a lower energy state.

This takes a long time. If you found a hydrogen atom all by its lonesome in the middle of empty space with parallel spins, and you waited and watched for it to flip back to its normal configuration, the average wait time is around 11 million years.

But here’s the kicker. Last time I checked there are way more than 11 million hydrogen atoms in the universe, which means if you have a whole bunch of hydrogen atoms all sitting around, chances are one of them is going to realign and release that pent-up energy.

And if you have, say, a galaxy’s worth of hydrogen atoms, then they’re emitting this energy pretty much all the time.

Now it’s not a lot of energy, around 5.8 micro electron-volts. That energy comes out in a very specific way, in the form of a single photon of electromagnetic radiation. And we can compute the wavelength of that radiation, and that comes out to 21 cm.

Every galaxy is glowing in this very special kind of light, all thanks to the humble hydrogen atom.

The post How Humble Hydrogen Lights Up the Universe appeared first on Universe Today.

Every Martian year (which last 686.98 Earth days), the Red Planet experiences regional dust storms that coincide with summer in the southern hemisphere. Every three Martian years (five and a half Earth years), these storms grow so large that they encompass the entire planet and are visible from Earth. These storms are a serious hazard for robotic missions, causing electrostatic storms that can mess with electronics and cause dust to build up on solar panels. In 2018 and 2022, the Opportunity Rover and InSight Lander were lost after dust storms prevented them from drawing enough power to remain operational.

But what about crewed missions? In the coming decades, NASA and the Chinese Manned Space Agency (CMS) plan to send astronauts and taikonauts to Mars. These missions will include months of surface operations and are expected to culminate in the creation of long-duration habitats on the surface. According to new research by the Keck School of Medicine at the University of Southern California (USC), Martian dust storms can potentially cause respiratory issues and elevated risk of disease, making them yet another health hazard space agencies need to prepare for.

The research was led by Justin L. Wang, a Doctor of Medicine at USC, along with several of his colleagues from the Keck School of Medicine. They were joined by researchers from the UCLA Space Medicine Center, the Ann and HJ Smead Department of Aerospace Engineering and the Laboratory for Atmospheric and Space Physics at UC Boulder, and the Astromaterials Acquisition and Curation Office at NASA’s Johnson Space Center. The paper detailing their findings appeared on February 12th in the journal GeoHealth.

Sending crewed missions to Mars presents many challenges, including logistics and health hazards. In the past 20 years, the shortest distance between Earth and Mars was 55 million km (34 million miles), or roughly 142 times the distance between the Earth and the Moon. This was in 2003 and was the closest the two planets had been in over 50,000 years. Using conventional methods, it would take six to nine months to make a one-way transit, during which time astronauts will experience physiological changes caused by long-term exposure to microgravity.

These include muscle atrophy, loss of bone density, a weakened cardiovascular system, etc. Moreover, a return mission could last as long as three years, during which time astronauts would spend at least a year living and working in Martian gravity (36.5% that of Earth). There’s also the risk of elevated radiation exposure astronauts will experience during transits and while operating on the surface of Mars. However, there are also the potential health effects caused by exposure to Martian regolith. As Wang described to Universe Today via email:

“There are many potential toxic elements that astronauts could be exposed to on Mars. Most critically, there is an abundance of silica dust in addition to iron dust from basalt and nanophase iron, both of which are reactive to the lungs and can cause respiratory diseases. What makes dust on Mars more hazardous is that the average dust particle size on Mars is much smaller than the minimum size that the mucus in our lungs is able to expel, so they’re more likely to cause disease.”

During the Apollo Era, the Apollo astronauts reported how lunar regolith would stick to their spacesuits and adhere to all surfaces inside their spacecraft. Upon their return to Earth, they also reported physical symptoms like coughing, throat irritation, watery eyes, and blurred vision. In a 2005 NASA study, the reports of six of the Apollo astronauts were studied to assess the overall effects of lunar dust on EVA systems, which concluded that the most significant health risks included “vision obscuration” and “inhalation and irritation.”

Artist’s depiction of a dust storm on Mars. Credit: NASA

“Silica directly causes silicosis, which is typically considered an occupational disease for workers that are exposed to silica (i.e., mining and construction),” said Wang. “Silicosis and exposure to toxic iron dust resemble coal worker’s pneumoconiosis, which is common in coal miners and is colloquially known as black lung disease.”

Beyond causing lung irritation and respiratory and vision problems, Martian dust is known for its toxic components. These include perchlorates, silica, iron oxides (rust), gypsum, and trace amounts of toxic metals like chromium, beryllium, arsenic, and cadmium – the abundance of which is not well understood. On Earth, the health effects of exposure to these metals have been studied extensively, which Wang and his team drew upon to assess the risk they pose to astronauts bound for Mars in the coming decades:

“It’s significantly more difficult to treat astronauts on Mars for diseases because the transit time is significantly longer than other previous missions to the ISS and the Moon. In this case, we need to be prepared for a wide array of health problems that astronauts can develop on their long-duration missions. In addition, [microgravity and radiation] negatively impact the human body, can make astronauts more susceptible to diseases, and complicate treatments. In particular, radiation exposure can cause lung disease, which can compound the effects that dust will have on astronauts’ lungs.”

In addition to food, water, and oxygen gas, the distance between Earth and Mars also complicates the delivery of crucial medical supplies, and astronauts cannot be rushed back to Earth for life-saving treatments either. According to Wang and his colleagues, this means that crewed missions will need to be as self-sufficient as possible when it comes to medical treatment as well. As with all major health hazards, they emphasize the need for prevention first, though they also identify some possible countermeasures to mitigate the risks:

“Limiting dust contamination of astronaut habitats and being able to filter out any dust that breaks through will be the most important countermeasure. Of course, some dust will be able to get through, especially when Martian dust storms make maintaining a clean environment more difficult. We’ve found studies that suggest vitamin C can help prevent diseases from chromium exposure and iodine can help prevent thyroid diseases from perchlorate.”

Austin Langton, a researcher at NASA’s Kennedy Space Center in Florida, creates a fine spray of the regolith simulant BP-1. Credits: NASA/Kim Shiflett

They also stressed that these and other potential countermeasures need to be taken with caution. As Wang indicated, taking too much vitamin C can increase the risk of kidney stones, which astronauts are already at risk for after spending extended periods in microgravity. In addition, an excess of idione can contribute to the same thyroid diseases that it is meant to treat in the first place. For years, space agencies have been actively developing technologies and strategies to mitigate the risks of lunar and Martian regolith.

Examples include special sprays, electron beams, and protective coatings, while multiple studies and experiments are investigating regolith to learn more about its transport mechanisms and behavior. As the Artemis Program unfolds and missions to Mars draw nearer, we are likely to see advances in pharmacology and medical treatments that address the hazards of space exploration as well.

Further Reading: GeoHealth

The post Should Astronauts Be Worried About Mars Dust? appeared first on Universe Today.

If Intermediate-Mass Black Holes (IMBHs) are real, astronomers expect to find them in dwarf galaxies and globular clusters. There’s tantalizing evidence that they exist but no conclusive proof. So far, there are only candidates.

The Dark Energy Spectroscopic Instrument (DESI) has found 300 additional candidate IMBHs.

Logic says that IMBHs should exist. We know of stellar-mass black holes, and we know of supermassive black holes (SMBHs). Stellar-mass black holes have between five and tens of solar masses, and SMBHs have at least hundreds of thousands of solar masses. Their upper limit is not constrained. Astrophysicists think these black holes are linked in an evolutionary sequence, so it makes sense that there’s an intermediate step between the two. That’s what IMBHs are, and their masses should range from about 100 to 100 thousand solar masses. IMBHs could also be relics of the very first black holes to form in the Universe and the seeds for SMBHs.

The problem is that there are no confirmed instances of them.

Omega Centauri, the brightest globular cluster in the Milky Way, is one of the prime candidates for an IMBH. There’s an ongoing scientific discussion about the cluster and the potential IMBH in its center. Stars in the cluster’s center move faster than other stars, indicating that a large mass is present. Some scientists think it’s an IMBH, while others think it’s a cluster of stellar-mass black holes.

This is Omega Centauri, the largest and brightest globular cluster that we know of in the Milky Way. An international team of astronomers used more than 500 images from the NASA/ESA Hubble Space Telescope spanning two decades to detect seven fast-moving stars in the innermost region of Omega Centauri. These stars provide compelling new evidence for the presence of an intermediate-mass black hole. Image Credit: ESA/Hubble & NASA, M. Häberle (MPIA)

Other evidence for IMBHs comes from a gravitational wave detection in 2019. The wave was generated by two black holes merging. The pair of black holes had masses of 65 and 85 solar masses, and the resulting black hole had 142 solar masses. The other 8 solar masses were radiated away as gravitational waves.

By adding 300 more IMBH candidates to the list, DESI may be nudging us toward a definitive answer about the existence of these elusive black holes.

The 300 new candidates are presented in a paper soon to be published in The Astrophysical Journal. It’s titled “Tripling the Census of Dwarf AGN Candidates Using DESI Early Data” and is available at arxiv.org. The lead author is Ragadeepika Pucha, a postdoctoral researcher at the University of Utah.

The 300 candidate IMBHs are the largest collection to date. Until now, there were only 100 to 150 candidates. This is a massive leap in the amount of available data, and future research will no doubt rely on it to make progress on the IMBH issue.

“Our wealth of new candidates will help us delve deeper into these mysteries, enriching our understanding of black holes and their pivotal role in galaxy evolution.”

Ragadeepika Pucha, University of Utah

The new candidates were identified in DESI’s early data release, which contains data from 20% of DESI’s first year of operations. The data included more than just IMBH candidates. DESI also found about 115,000 dwarf galaxies and spectra from about 410,000 galaxies, a huge number.

This mosaic shows a series of images featuring candidate dwarf galaxies hosting an active galactic nucleus, captured with the Subaru Telescope’s Hyper Suprime-Cam. Image Credit: Legacy Surveys/D. Lang (Perimeter Institute)/NAOJ/HSC Collaboration/D. de Martin (NSF NOIRLab) & M. Zamani (NSF NOIRLab)

The data allowed lead author Pucha and her colleagues to explore the relationship between the evolution of dwarf galaxies and black holes.

Despite their extreme masses, black holes are difficult to find. Their presence is inferred from their effect on their environment. In their presence, stars are accelerated to high velocities. Fast-moving stars were one of the clues showing that the Milky Way has an SMBH.

Astronomers are pretty certain that all massive galaxies like ours host an SMBH in their centers, but this certainty fades when it comes to dwarf galaxies. Dwarf galaxies are so small that our instruments struggle to observe them in detail. Unless the black hole is actively feeding.

When a black hole is actively consuming material, it is visible as an active galactic nucleus (AGN.) AGNs are like beacons that alert astronomers to the presence of a black hole.

“When a black hole at the center of a galaxy starts feeding, it unleashes a tremendous amount of energy into its surroundings, transforming into what we call an active galactic nucleus,” lead author Pucha said in a press release. “This dramatic activity serves as a beacon, allowing us to identify hidden black holes in these small galaxies.”

The team found 2,500 dwarf galaxies containing an active galactic nucleus, an astonishing number. Like the new IMBH candidates, this is the largest sample ever discovered. The researchers determined that 2% of the dwarf galaxies hosted AGN, a big step up from the 0.5% gleaned from other studies.

“This increase can be primarily attributed to the smaller fibre size of DESI compared to SDSS <Sloan Digital Sky Survey>, which aids with the identification of lower luminosity AGN within the same magnitude and redshift range,” the authors explain in their paper.

This artist’s illustration depicts a dwarf galaxy that hosts an active galactic nucleus — an actively feeding black hole. In the background are many other dwarf galaxies hosting active black holes, as well as a variety of other types of galaxies hosting intermediate-mass black holes. Image Credit: NOIRLab/NSF/AURA/J. da Silva/M. Zamani

Astronomers think that black holes found in dwarf galaxies should be within the intermediate-mass range. However, only 70 of the newly discovered IMBH candidates overlap with dwarf AGN candidates. This is unexpected and raises yet more questions about black holes, how they form, and how they evolve within galaxies.

This scatter plot, adapted from the research, shows the number of candidate dwarf galaxies hosting active galactic nuclei (AGN) from previous surveys compared with the number of new dwarf galaxy AGN candidates discovered by the Dark Energy Spectroscopic Instrument (DESI). Image Credit: NOIRLab/NSF/AURA/R. Pucha/J. Pollard

“For example, is there any relationship between the mechanisms of black hole formation and the types of galaxies they inhabit?” Pucha said. “Our wealth of new candidates will help us delve deeper into these mysteries, enriching our understanding of black holes and their pivotal role in galaxy evolution.”

DESI is only getting started. These discoveries were made with only a small portion of data from the instrument’s first year of operation, and there are several more years of operation to come.

“The anticipated increase in the sample of dwarf AGN candidates over the next five years with DESI will accelerate studies of AGN in dwarf galaxies,” the authors write in their research. “The statistical sample of dwarf AGN candidates will be invaluable for addressing several key questions related to galaxy evolution on the smallest scales, including accretion modes in low-mass galaxies and the co-evolution of galaxies and their central BHs,” they conclude.

• Press Release: DESI Uncovers 300 New Intermediate-Mass Black Holes Plus 2500 New Active Black Holes in Dwarf Galaxies
• Research: Tripling the Census of Dwarf AGN Candidates Using DESI Early Data
• Research: Properties and Astrophysical Implications of the 150 M? Binary Black Hole Merger GW190521
• Research: New constraints on the central mass contents of Omega Centauri from combined stellar kinematics and pulsar timing

The post DESI Found 300 Candidate Intermediate Mass Black Holes appeared first on Universe Today.

There are plenty of types of stars out there, but one stands out for being just a little weirder than the others. You might even say it’s strange. According to a paper from researchers at Guangxi University in China, the birth of one might have recently been observed for the very first time.

A strange star is a (so far theoretical) compact star that is so dense it literally breaks down regular parts of atoms (like neutrons) into their constituent quarks. Moreover, even those quarks (the up and down that comprise a neutron) get compressed into an even rarer type of quark called a strange quark – hence the name strange star.

Technically, the “strange” matter that a strange star would be composed of is a combination of up, down, and strange quarks. But, at least in theory, this mix of sub-hadronic particles could even be more stable than a traditional neutron star, which is similar to a strange star but doesn’t have enough gravity to break down the neutrons.

Fraser discusses strange stars.

Strange stars, though they exist in theory, are exceedingly rare. No one has ever proven that one exists. But Xiao Tian and his co-authors think they might have found evidence of one.

Their paper describes a recent gamma-ray burst known as GRB 240529A that they think holds the clues to finding a strange star. Gamma-ray bursts, the gigantic implosions that sometimes result from creating a black hole, could also have other causes – or “central engines,” as they are called in the literature. One such central engine is the creation of a magnetar.

Magnetars are another type of neutron star that is even more extreme. Their magnetic fields could be up to 1,000 times that of a typical neutron star, giving them the largest magnetic fields in the known universe. In them, electrons and protons are forced together to create neutrons, hence the name neutron star.

Fraser discusses magnetars, the type of star that would theoretically collapse into a strange star.

However, they could also collapse upon themselves, as a part of cosmological theory allows for a magnetar to collapse into an even more dense form, which would be something akin to a strange star with the requisite mix of quarks. Doing so would undoubtedly produce a gamma-ray burst, which Dr. Tian and his co-authors believe they found in GRB 240529A.

The details of that particular GRB hold the clues. There were three distinct “emission episodes” that represented different phases of the collapse to a magnetar, then to a strange star, and then the spin-down of the strange star. A different spectrum of gamma rays represents each as part of the burst, and each episode was separated by a few hundred seconds of relative calm, which seems like an exceedingly short time considering how massive the objects were collapsing. 

Moreover, in the X-ray spectrum, another part of the light curve could be described as containing “plateaus.” According to the authors, each of these plateaus could represent a stage in the birth of the strange star, with the first representing its cooling and the second representing its “pin down” phase.

According to their calculations, the observed data best matches the theoretical values that would be seen if GRB represented the birth of a strange star. So it seems likely that, for the first time, astronomers have garnered some evidence to support a theory that was initially developed in the 1980s. But, as always, more testing is needed, and other researchers should confirm the authors’ calculations. But if they do, it would be a significant leap forward in experimental astrophysics – and may herald many more strange findings to come.

Learn More:
Tian et al – Signature of strange star as the central engine of GRB 240529A
UT – It Takes Very Special Conditions to Create This Bizarre Stellar Spectacle
UT – SLS Hurricanes, James Webb Fixed, Strange Quark Star
UT – The Mysterious Case of the Resurrected Star

Lead Image:
Illustration of the interior of a neutron star and a strange quark star
Credit – NASA/SAO/CXC/J.Drake et al.

The post Did Astronomers Just Witness the Formation of a “Strange Star”? appeared first on Universe Today.

As far as we can tell, life needs water. Cells can’t perform their functions without it. Some have suggested that other exotic liquids, like liquid methane, could do the job on worlds like Saturn’s moon Titan. That idea is highly speculative, though.

So, it makes sense that NASA is launching a spacecraft dedicated to the search for water.

SPHEREx stands for Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer. It’s scheduled to launch on February 27th. It has a single instrument and one observing mode. Part of its mission is to map the sky in near-infrared and measure the spectra of 450 million galaxies. The results will help scientists understand the expansion of the Universe and the origin and evolution of galaxies.

This image shows a semi-frontal view of the SPHEREx observatory during integration and testing at BAE Systems (Boulder, CO). Image Credit: NASA/JPL-Caltech.

Its other scientific goal is to probe molecular clouds for water ice and other frozen pre-biotic molecules. These ices are frozen onto the surface of dust grains in molecular clouds, and somehow, through a long journey, they become part of planets, where they can form oceans and potentially foster the appearance of life.

Infrared observations show that in cold, dense regions of space in molecular clouds, chemicals critical to life are locked into dust grains. Water is the primary one, of course, but there are other pre-biotic molecules as well: carbon dioxide (CO2), carbon monoxide (CO), methanol (CH3OH), the nitrogen-bearing molecule ammonia (NH3) plus various carbon-nitrogen stretch molecules (XCN), and the important sulphur-bearing molecule, carbonyl sulphide (COS). Carbon-nitrogen stretch molecules are everywhere in organic and biological molecules and play critical roles in biological processes. Carbonyl-sulphide plays a role in the formation of peptides, which are the building blocks of proteins.

There’s a vast amount of water frozen in dust grains in molecular clouds, and scientists think this is where the bulk of the water in the galaxy and even in the Universe resides. These grains are the source of water for Earth’s oceans and for any exoplanets or moons that might harbour oceans.

SPHEREx will examine molecular clouds and try to understand how much water they contain. It will also examine stars in those clouds and the rings of material that form around them, out of which planets form.

Put succinctly, SPHEREx is trying to answer this question: How does ice content evolve from diffuse clouds to dense clouds to planetary disks and then to planets?

This photo by renowned astrophotographer Rogelio Bernal Andreo shows the Orion constellation and the surrounding nebulas of the Orion Molecular Cloud complex. The clouds in the complex hold frozen water and other chemicals critical to life. Image Credit: By Rogelio Bernal Andreo – http://deepskycolors.com/astro/JPEG/RBA_Orion_HeadToToes.jpg, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=20793252

There’s little doubt that ices play an important role in the formation of planetesimals in disks around young stars. Likewise, there’s little doubt that these ices are sources of water and organic molecules, too. But how does it all happen? Ice’s journey from translucent to dense molecular clouds and then to protoplanetary disks is not well understood. Scientists want to know if the ices in the disks are simply inherited from the interstellar medium or if they’re altered in the disks somehow.

The SPHEREx mission hopes to answer this question and others with its infrared absorption spectroscopy.

SPHEREx will generate spectra for between 8 and 9 million sources and should transform our understanding of ices in molecular clouds, young stellar objects, and protoplanetary disks.

In infrared wavelengths, ices have unique spectral signatures. Prior to the JWST, scientists had only about 200 ice absorption spectra available. The JWST is changing that, but it has lots of other important work to do.

The JWST is already advancing our understanding of these ices. Like other infrared observatories, it can see through dust, but it is far more powerful and sensitive. A key to SPHEREx’s design and performance is its ability to be as accurate as the JWST.

The black line is the JWST spectrum of a source seen through a thick molecular cloud of interstellar dust, showing the strong features of the interstellar ice species H2O, CO2, and CO at wavelengths of 3.05, 4.27, and 4.67 microns (McClure et al. 2023, Nature Astronomy, 7, 431). Overlaid in red is a simulated spectrum, taken with SPHEREx’s lower spectral resolving power, of a background source with 100x the JWST brightness in the SPHEREx range that shows the same absorption features as seen by JWST. Note that SPHERE reproduces almost all of the spectral structure apparent in the JWST spectrum. Image Credit: NASA/JPL

There is no shortage of targets for SPHEREx. Some research shows that there are over 8,000 molecular clouds in the Milky Way. Not all of them are great targets for SPHEREx, but many are.

SPHEREx has a catalogue of targets that includes molecular clouds in the Large and Small Magellanic Clouds and several constellations, including Monoceros, home of the Monoceros R2 Molecular Cloud.

The Monoceros R2 Molecular Cloud is one of SPHEREx’s targets. This image shows only a portion of the cloud, which is a large cloud with lots of active star formation. Star formation is particularly active in the location of the bright red nebula just below the center of the image. This image was obtained with the wide-field view of the Mosaic II camera on the Blanco 4-meter telescope at Cerro Tololo Interamerican Observatory on January 11th, 2012. Image Credit: T.A. Rector (University of Alaska Anchorage) and N.S. van der Bliek (NOIRLab/NSF/AURA)

It’s axiomatic that stars and planets have the same compositions as the molecular clouds that fostered them. But the specifics of planet formation are mysterious and the study of the processes has produced some surprises.

In 1998, NASA launched the Submillimeter Wave Astronomy Satellite (SWAS). Similar to SPHEREx, it studied the chemical composition of interstellar clouds and surveyed the galaxy to determine how much water vapour was present in molecular clouds. Surprisingly, it found far less than expected.

“This puzzled us for a while,” said Gary Melnick, a senior astronomer at the Center for Astrophysics | Harvard & Smithsonian and a member of the SPHEREx science team. “We eventually realized that SWAS had detected gaseous water in thin layers near the surface of molecular clouds, suggesting that there might be a lot more water inside the clouds, locked up as ice.”

The SWAS team figured out that hydrogen and oxygen atoms were being frozen onto the surfaces of ice grains where they formed water ice. Subsequent research confirmed their suspicions. On the unprotected surfaces of molecular clouds, cosmic radiation can break the H2O molecules apart, but protected inside molecular clouds, the molecules persisted.

The water ice and other ices create spectroscopic signatures separate from their liquid counterparts, and SPHEREx is designed to detect them.

It will do more than detect them, though. The spacecraft will also determine how deep inside the clouds the ices form, how their abundance changes with cloud density, and how the abundance changes when a star forms.

SPHEREx will also cooperate with other telescopes, including the JWST, which will perform more powerful follow-up observations when merited.

“If SPHEREx discovers a particularly intriguing location, Webb can study that target with higher spectral resolving power and in wavelengths that SPHEREx cannot detect,” said Melnick. “These two telescopes could form a highly effective partnership.”

SPHEREx will launch on February 27th in a Falcon Heavy rocket from Vandenberg Air Base. It will follow a Sun-Synchronous orbit at about 700 km altitude. In its nominal 25-month mission, SPHEREx will map the entire sky four times.

• Press Release: NASA’s SPHEREx Space Telescope Will Seek Life’s Ingredients
• CalTech SPHEREx Science
• An All-Sky Spectral Survey
• The Astrophysical Journal: The SPHEREx Target List of Ice Sources (SPLICES)
• JPL: The Origin of Water – and Other Pre-biotic Molecules – in Planetary Systems

The post NASA’s SPHEREx Launches Soon and Will Search For Water in Molecular Clouds appeared first on Universe Today.

Dubbed CADRE, a trio of lunar rovers are set to demonstrate an autonomous exploration capability on the Moon.

An exciting Moon mission launching in the next year will perform a first, deploying multiple rovers. These will talk to each other and a remote base station, demonstrating an autonomous exploration capability.

The three Cooperative Autonomous Distributed Robotic Exploration (CADRE) rovers were recently packaged and shipped from their home at NASA’s Jet Propulsion Laboratory in Pasadena, California. Each about the size of a small suitcase, the CADRE rovers will launch from LC-39A at the Kennedy Space Center in Florida on a SpaceX Falcon-9 rocket with Intuitive Machines’ IM-3 mission in late 2025 or early 2026. The ultimate destination is the enigmatic Reiner Gamma region in the Oceanus Procellarum (Ocean of Storms) region on the lunar nearside.

Robotic lunar rovers go all the way back to the late Soviet Union’s Lunokod-1 rover on the Luna 17 mission in 1970. CADRE, however, will demonstrate that three rovers can work in unison for lunar exploration. This sort of rover network could come in handy, allowing astronaut controllers to one day explore regions too dangerous to venture into.

A CADRE rover undergoes a vibration test ahead of launch. Credit: NASA/JPL A Robotic Lunar Trio

To this end, the Nova-C lander will lower the solar-powered rovers to the surface shortly after touchdown. Engineers equipped each rover with cameras and ground-penetrating radars for exploration. Controllers expect the rovers to last two weeks (14 days) on the surface, from local sunrise to sunset.

“Our small team worked incredibly hard constructing these robots and putting them to the test,” says Coleman Richdale (NASA-JPL) in a recent press release. “We are all genuinely thrilled to be taking this next step in our journey to the Moon, and we can’t wait to see the lunar surface through CADRE’s eyes.”

This will mark Intuitive Machines’ third delivery to the lunar surface. Part of NASA’s CLPS (Commercial Lunar Payload Services) initiative, The company’s IM-1 mission and Nova-C lander Odysseus made an askew landing at the Malapert A crater early last year. The company will make another attempt with the launch of IM-2 next week on February 26th. The mission will carry NASA’s PRIME-1 (Polar Resources and Ice Mining Experiment) with The Regolith and Ice Drill for Exploring New Terrain (TRIDENT) 1-meter drill. The mission is headed to the Shackleton connecting ridge site in the lunar South Pole region.

A Mars rover twin versus a CADRE rover at JPL’s ‘Mars Yard’. Credit: NASA/JPL

Meanwhile, another CLPS mission, Firefly Aerospace’s Blue Ghost will land on the Moon on March 2nd.

The Reiner Gamma landing site is a high priority target for exploration. Astronomers recognize the feature as one of the best known examples of a ‘lunar swirl’. It’s also a known site for localized magnetic anomalies. What causes swirls on the lunar surface isn’t entirely clear. They definitely stand out in stark contrast to the typical pockmarked, cratered surface of the Moon.

The location of the Reiner Gamma landing site on the lunar nearside. Credit: Dave Dickinson (inset: NASA/LRO). What Else is Aboard IM-3?

In addition to CADRE, several other experiments are hitching a rideshare trip to the Moon aboard IM-3. These include Lunar Vertex (LVx), a joint lander-rover also looking to explore the magnetic anomalies of Reiner Gamma, and the Korea Astronomy Space Science Institute (KASI)’s Lunar Space Environment Monitor (LUSEM) which will monitor the near-surface space environment on the Moon. Also on board is a pointing actuator experiment for the European Space Agency’s MoonLIGHT network. This is a precursor to the agency’s Lunar Geophysical Network for laser ranging and pinpoint measurements.

The CADRE Team plus the trio of rovers, headed to the Moon. Credit: NASA/JPL-Caltech

The Moon is about to become a busy place. It’ll be exciting to see CADRE and other missions resume lunar exploration in the coming years.

The post CADRE’s Three Adorable Rovers Are Going to the Moon appeared first on Universe Today.

Astronomers have identified sulfur as a potentially crucial indicator in narrowing the search for life on other planets. While sulfur itself is not necessarily an indication of habitability, significant concentrations of sulfur dioxide in a planet’s atmosphere can suggest that the planet is likely uninhabitable, allowing researchers to eliminate it from further consideration.

The discovery of extraterrestrial life remains one of the most sought-after objectives in modern astronomy. However, this is a formidable challenge. The James Webb Space Telescope is unlikely to detect biosignatures—atmospheric gases produced by living organisms—in nearby planets. Similarly, the upcoming Habitable Worlds Observatory will only be able to assess a limited number of potentially habitable exoplanets.

One of the primary obstacles astronomers face is the typically faint nature of biosignature spectra. To address this, they focus on the potential for planets to host life, particularly through the presence of water vapor in their atmospheres. A planet with substantial water vapor may be more likely to support life.

This concept is encapsulated in the “Habitable Zone,” the region around a star where a planet receives just the right amount of radiation: not too little to freeze all water, and not too much to boil it away. In our solar system, Venus lies near the inner edge of the Habitable Zone with surface temperatures exceeding 800 degrees Fahrenheit beneath a dense atmosphere, while Mars resides primarily outside the zone, its water largely trapped in polar ice caps and subsurface reservoirs.

However, detecting water alone poses challenges. For instance, distinguishing between Earth and Venus based solely on atmospheric spectra is difficult due to their similarities when only searching for water vapor.

Recently, a team of astronomers has identified another potentially useful indicator gas for differentiating uninhabitable from possibly habitable worlds: sulfur dioxide. Warm, wet planets like Earth contain minimal sulfur dioxide because it is washed out of the atmosphere by rain. Conversely, Venus also has little detectable sulfur dioxide, as ultraviolet radiation from the Sun converts it into hydrogen sulfide in the upper atmosphere, driving it downwards.

Planets orbiting red dwarf stars present another scenario. These stars emit minimal ultraviolet radiation, allowing sulfur dioxide to persist in the upper atmospheres of dry, uninhabitable planets. Red dwarfs are of particular interest because they are the most common type of star in the galaxy, and many nearby systems, such as Proxima Centauri and TRAPPIST-1, host planets around red dwarfs, making them prime targets for future searches for life.

This new approach involving sulfur dioxide does not identify planets that might harbor life but helps exclude those that likely do not. If significant sulfur dioxide is detected in the atmosphere of a rocky planet orbiting a red dwarf, it suggests a dry, hot world with a thick atmosphere and little to no water, akin to Venus. Such planets can be deprioritized in the search for life.

Conversely, the absence of significant sulfur dioxide may indicate a planet worth further observation for signs of water vapor and potential life.

The quest to find life on other planets will require extensive investigative efforts and unwavering determination. Any method, including the analysis of sulfur dioxide levels to streamline candidate lists, is highly valuable in this endeavor.

The post What’s That Smell? It’s Sulfur – A New Tool For Finding Alien Life appeared first on Universe Today.

Biologists identified a series of “hard steps” on the journey from abiogenesis – that life evolved naturally from non-living matter – to modern civilisation. These steps, such as the evolution of multi-cellular organisms or even language make the stark suggestion that intelligent life is highly improbable! Instead, the researchers propose that human-like life could be a natural outcome of planetary evolution, increasing the likelihood of intelligent life elsewhere. 

The hard-steps model of the evolution of life suggests that the development of complex life depends on a series of highly improbable events, or “hard steps,” that must occur in a specific order. Each step marks a major evolutionary transition—such as complex cells, multicellularity, and intelligence. These steps are rare and require precise conditions, according to the theory, making complex life an unlikely outcome. This model explains why intelligent life seems so scarce, despite the vast number of potentially habitable planets, as the long timescales for each step contribute to its rarity.

An artist’s conception of Tau Ceti e, a possible ‘exo-Earth’ in the habitable zone. Ph03nix1986/Wikimedia Commons/CCA 4.0

The model was originally developed in 1983 by Brandon Carter, an Australian theoretical physicist. It’s conclusion has now been challenged by a team of scientists including astrophysicists and astrobiologists. They argue that the inhospitable young Earth would have gone through environmental changes and it was these that facilitated the ‘hard-steps.’ An example of this is the requirement for complex animal life on a certain level of oxygen in the atmosphere. Before the atmosphere could sustain the levels of oxygenation it was difficult for complex life to evolve, after the event, the liklihood was for greater. 

A view of Earth’s atmosphere from space. Credit: NASA

In their new study, the researchers suggested that the evolution of humans can be associated to the gradual emergence of “windows of habitability” throughout Earth’s history. These windows are thought to have been influenced by shifts in nutrient availability, sea surface temperatures, ocean salinity, and atmospheric oxygen levels. They explained that, considering all these factors, Earth has only recently become suitable for human life.

The collaborative paper between disciplines was effective due to the learning gained from each other’s fields. It developed a new picture of how life evolved on the Earth. The team plan to test their new model which even questions the ‘hard steps’ theory. They suggest other pieces of work that will help to corroborate – or otherwise – their theory such as the search for biosignatures in exoplanetary atmospheres. They also suggest it would be suitable to test the requirements for the so called ‘hard steps’ and try to understand just how hard they really are. Using unicellular and multicellular forms of life, the team want to explore the impact of specific environmental conditions. 

The team are keen to explore other innovations within multicellular Homo sapiens, photosynthesis and eukaryotic cellular environment. It’s possible that similar innovations may have evolved independently in the past. Although the researchers acknowledge that extinction events may have eradicated such evidence. 

Source : Does planetary evolution favor human-like life? Study ups odds we’re not alone

The post Is Intelligent Life Inevitable? appeared first on Universe Today.

The supermassive black hole at the center of our Milky Way galaxy may not be as voracious as the gas-gobbling monsters that astronomers have seen farther out in the universe, but new findings from NASA’s James Webb Space Telescope reveal that its surroundings are flaring with fireworks.

JWST’s readings in two near-infrared wavelengths have documented cosmic flares that vary in brightness and duration. Researchers say the accretion disk of hot gas surrounding the black hole, known as Sagittarius A*, throws off about five or six big flares a day, and several smaller bursts in between.

The observations are detailed today in The Astrophysical Journal Letters.

“In our data, we saw constantly changing, bubbling brightness. And then boom! A big burst of brightness suddenly popped up. Then, it calmed down again,” study lead author Farhad Yusef-Zadeh of Northwestern University in Illinois said in a news release. “We couldn’t find a pattern in this activity. It appears to be random. The activity profile of this black hole was new and exciting every time that we looked at it.”

Yusef-Zadeh and his colleagues observed Sagittarius A* using JWST’s Near-Infrared Camera, or NIRCam, for a total of 48 hours, broken up into eight- to 10-hour increments over the course of a year. They expected to see flares, but they didn’t expect the black hole’s surroundings to be as active as they are.

The researchers suggest that two separate processes are sparking the light show. The smaller flares may be due to turbulence in the accretion disk, compressing the disk’s hot, magnetized gas. Such disturbances could throw off brief bursts of radiation that Yusef-Zadeh likens to solar flares.

“It’s similar to how the sun’s magnetic field gathers together, compresses and then erupts a solar flare,” he explained. “Of course, the processes are more dramatic because the environment around a black hole is much more energetic and much more extreme.”

The bigger bursts could be due to magnetic reconnection events. That would occur when two magnetic fields collide, throwing off bright blasts of particles that travel at velocities near the speed of light. “A magnetic reconnection event is like a spark of static electricity, which, in a sense, also is an ‘electric reconnection,’” Yusef-Zadeh said.

Another unexpected finding has to do with how the flares brighten and dim when seen in two different wavelengths. Events observed at the shorter wavelength changed brightness slightly before the longer-wavelength events.

“This is the first time we have seen a time delay in measurements at these wavelengths,” Yusef-Zadeh said. “We observed these wavelengths simultaneously with NIRCam and noticed the longer wavelength lags behind the shorter one by a very small amount — maybe a few seconds to 40 seconds.”

Those observations could serve as clues to the physical processes at work in the disk swirling around the black hole. It could be that the particles thrown off by the flares lose energy more quickly at shorter wavelengths than at longer wavelengths. That’s the pattern you’d expect for particles spiraling around magnetic field lines in a cosmic synchrotron.

Now researchers are hoping to get a longer stretch of time on JWST, which should help them reduce the noise in their observations and produce a more detailed picture of what’s going on at the center of our home galaxy.

“When you are looking at such weak flaring events, you have to compete with noise,” Yusef-Zadeh said. “If we can observe for 24 hours, then we can reduce the noise to see features that we were unable to see before. That would be amazing. We also can see if these flares repeat themselves, or if they are truly random.”

In addition to Yusef-Zadeh, the authors of the study in The Astrophysical Journal Letters, “Nonstop Variability of Sgr A* Using JWST at 2.1 and 4.8 ?m Wavelengths: Evidence for Distinct Populations of Faint and Bright Variable Emission,” include H. Bushouse, R.G. Arendt, M. Wardle, J.M. Michail and C.J. Chandler.

The post Webb Space Telescope Tracks Fireworks Around Our Galaxy’s Black Hole appeared first on Universe Today.