SPACE/COSMOS
Artemis II astronauts witness total solar eclipse after restoring contact with Earth
NASA’s Artemis II astronauts sent detailed observations of the Moon after traveling farther from Earth than any human before, breaking Apollo 13’s distance record. Mission control regained contact after a 40-minute blackout behind the Moon, with the crew expressing relief as communications were restored with Earth.
Issued on:07/04/2026 -FRANCE 24
The four astronauts carrying out NASA's first lunar flyby in more than half-a-century were sending back detailed observations of the Moon after traveling further from Earth than any human before.
NASA's mission control in Houston regained contact with the crew after they temporarily lost signal for some 40 minutes, as their spacecraft passed behind Earth's natural satellite.
"It is so great to hear from Earth again," said astronaut Christina Koch, as the crewmembers were once again able to speak with humans on their home planet.
"We will always choose Earth, we will always choose each other."
Earlier the Artemis II team broke the distance record set by the 1970 Apollo 13 mission, which they were expected to surpass by 4,105 miles (6,606 kilometers) when they reached the journey's anticipated furthest distance from Earth -- 252,760 miles (406,778 kilometers).
It was one of the voyage's most notable achievements yet.
Astronaut Jeremy Hansen said the moment was "to challenge this generation and the next, to make sure this record is not long-lived."
The lunar flyby observation period will continue until approximately 9:20pm eastern (0120 GMT).
Soon astronauts will witness a solar eclipse, when the Sun will be behind the Moon.
'Wow'
The more than six-hour task of observing and documenting the lunar surface brought human perspective to features of the Moon that we primarily know through photographs taken by robots.
Victor Glover detailed the "terminator" -- the Moon's boundary between night and day.
"Wow -- I wish I had some more time to just sit here and describe what I'm seeing," he said, before creating a vivid portrait for the scientists listening in from Earth.
"But the terminator right now is just fantastic. It is the most rugged that I've seen it from a lighting perspective."
Kelsey Young, the lead scientist for the Artemis II mission, responded with elation. "Oh my gosh, that was an amazing picture you just painted," she said.
"Those types of observations are things that humans are uniquely able to contribute, and you just really brought us along with you."
Fellow astronaut Christina Koch meanwhile offered a colorful rendering of lunar craters.
"What it really looks like is like a lampshade with tiny pinprick holes and the light shining through," she said. "They are so bright compared to the rest of the Moon."
Moon memorials
The Orion capsule is zipping around the Moon before U-turning and heading back to Earth in a so-called "free-return trajectory," a return-trip that will take about four days.
Adding to the historic nature of the mission led by Reid Wiseman, the Artemis II crew includes several firsts.
Glover will be the first person of color to fly around the Moon, Koch will be the first woman, and Canadian Hansen the first non-American.
Monday's celestial workday included a poignant moment just after the crew broke the distance record, when they proposed designating two previously unnamed craters.
The first they requested to name in honor of their spacecraft's nickname, "Integrity."
They offered a second name, "Carroll," for another crater, which they asked be named after the late wife of mission commander Reid Wiseman, who died of cancer.
"It's a bright spot on the Moon," said Hansen, his voice breaking with emotion. "And we would like to call it Carroll."
The astronauts embraced, and mission control in Houston held a moment of silence.
"Integrity and Carroll crater, loud and clear. Thank you," said Gibbons.
NASA said they would formally submit the name proposals to the International Astronomical Union, the body charged with naming celestial bodies and surface features.
Watch NASA's coverage of the lunar flyby by clicking on the player here:
NASA's Artemis II Live Mission Coverage
Nasa’s Artemis II crew to reach unseen far side of the Moon on flyby
NASA’s Artemis II crew are expected to reach their destination on Monday where the four astronauts aboard the Orion will – for the first time – look at the lunar far side with the naked eye. The fly-by will last approximately six hours before the astronauts head back home.
Astronauts aboard NASA's Artemis II lunar mission are more than halfway through their historic expedition, during which they will fly by the Moon and push deeper into space than even Apollo astronauts did more than 50 years ago.
Three American astronauts and one Canadian astronaut lifted off from Kennedy Space Centre in Florida on the 1st of April for a nearly 10-day mission, during which they will photograph the mysterious lunar far side as they travel past it.
The mission, humanity’s first trip to the Moon since 1972, is chasing Apollo 13's record for the farthest distance from Earth. That will make them our planet’s farthest emissaries as they swing around the Moon without stopping on Monday and then hightail it back home.
Their roughly six-hour lunar flyby promises views of the Moon’s far side that were too dark or too difficult to see by the 24 Apollo astronauts who preceded them. A total solar eclipse also awaits them as the Moon blocks the Sun, exposing snippets of shimmering corona.
“We’ll get eyes on the Moon, kind of map it out and then continue to go back in force,” said flight director Judd Frieling. The goal is a Moon base replete with landers, rovers, drones and habitats.
Apollo 13's astronauts missed out on a Moon landing when one of their oxygen tanks ruptured on the way there in 1970.
With the three lives in jeopardy, Mission Control pivoted to a free-return lunar trajectory to get them home as fast and efficiently as possible. This routing relies on the gravity of Earth and the Moon, and minimal fuel.
It worked for Apollo 13, turning it into what was later dubbed as NASA’s greatest “successful failure.”
Commander Jim Lovell, Fred Haise and Jack Swigert reached a maximum 400,171 kilometres from Earth before making their life-saving U-turn on Apollo 13.
Artemis II’s astronauts are following the same figure-eight path since they are neither orbiting the Moon nor landing on it. But their distance from Earth should exceed Apollo 13’s by more than 6,600 kilometres.
The mission’s Christina Koch said late last week that she and her crewmates don’t live on superlatives, but it’s an important milestone “that people can understand and wrap their heads around,” one that merges the past with the present and even the future as new records are set.
During the flyby, the astronauts will split into pairs and take turns capturing the lunar views out their windows with cameras. At closest approach, they will come within 6,550 kilometres of the Moon.
Because they launched on 1 April, the rendezvous will not see as much of the far lunar side illuminated as on other dates.
But the crew still will be able to make out “definite chunks of the far side that have never been seen” by humans, said NASA geologist Kelsey Young, including a good portion of Orientale Basin.
Once Artemis II departs the lunar neighbourhood, it will take four days to return home. The capsule will aim for a splashdown in the Pacific near San Diego on April 10, nine days after its Florida launch.
During the flight back, the astronauts will link up via radio with the crew of the orbiting International Space Station, where NASA colleagues are poised to have a cosmic chitchat.
"Ancient Immigrant" star puzzles, delights astronomers
Sloan Digital Sky Survey
image:
An image of our Milky Way galaxy with the position of the Ancient Immigrant star (SDSS J0715-7334) marked with a star symbol. The solid red line shows the path the Ancient Immigrant has taken through our galaxy; the dashed blue line shows the path expected for a star born in the Large Magellanic Cloud.
view moreCredit: Image Credit: Vedant Chandra and the SDSS collaboration Background ESA/Gaia image, A. Moitinho, A. F. Silva, M. Barros, C. Barata, University of Lisbon; H. Savietto, Fork Research, under a Creative Commons license CC BY‐SA 3.0 IGO.
A class of undergraduate students at University of Chicago has used data from the Sloan Digital Sky Survey (SDSS) to discover one of the oldest stars in the universe, a star that formed in a companion galaxy and migrated to the Milky Way.
The ten students found the star as part of their “Field Course in Astrophysics” course at the University of Chicago, led by Professor Alex Ji, the deputy Project Scientist for SDSS-V, and graduate teaching assistants Hillary Andales and Pierre Thibodeaux.
SDSS, an international collaboration of over 75 scientific institutions across the globe, has been operating for 25 years with a commitment to make data from its survey publicly available and broadly usable to all. In its latest phase, it uses robots to rapidly acquire spectra of millions of objects across the sky with the aim of improving our understanding of how stars, black holes and galaxies grow and evolve over cosmic time.
In Professor Ji’s class, SDSS is embedded into the curriculum. The students spent the first several weeks looking through data from the newest phase of the SDSS, searching for interesting stars. After examining several thousand, they made a list of 77 to further observe on a field trip to Las Campanas Observatory.
They then spent their Spring Break at Carnegie Science’s Las Campanas Observatory in Chile, using the Magellan Inamori Kyocera Echelle (MIKE) instrument on the Magellan telescopes. The night of March 21st, 2025 was their first night on the telescope. The second star they observed, named SDSSJ0715-7334, turned out to be the one that justified the trip.
“We found it the first night, and it completely changed our plans for the course,” Ji said.
The plan was to observe each star for 10 minutes, but the second night the students observed it for three hours. “I was looking at that camera the whole night to make sure it was working,” said Natalie Orrantia, one of the students who made the discovery.
The star turned out to be the most pristine ever found, composed almost completely of hydrogen and helium. This composition suggests it is one of the oldest stars ever seen. Analysis of its orbit shows it formed in the Large Magellanic Cloud and migrated into the Milky Way billions of years ago. These two facts led Alex Ji, the students’ Professor at University of Chicago, to call the star an “ancient immigrant.”
“This ancient immigrant gives us an unprecedented look at conditions in the early universe,” said Ji. “Big data projects like SDSS make it possible for students to get directly involved in these important discoveries.”
Astronomers refer to any elements heavier than hydrogen and helium as “metals,” and the amount of those elements present in a star is known as its “metallicity.” With only 0.005 percent of the metals found in our Sun, SDSSJ0715-7334 has the lowest metallicity of any star yet observed in the Universe – more than twice as metal-poor as the previous record holder.
“We analyzed the star for a large swath of elements, and the abundances are quite low for all of them,” said Ha Do, another of the students who discovered the star.
What does it mean for a star to have low metallicity? Because elements heavier than hydrogen and helium can only be produced in supernova explosions, stars with few of these elements must have formed from gas before most of the supernovae in the Universe ever occurred. In other words, the star must be ancient, from the first few generations of stars that ever formed.
The team also used data from the European Space Agency’s Gaia mission to find the distance to the star and its motion through our galaxy. By tracing its motion back through the billions of years the star has existed, the team identified the birthplace of the star: in the Milky Way’s largest companion galaxy, the Large Magellanic Cloud.
The Ancient Immigrant contained further surprises for the students who discovered it. Ji divided the class into groups, each focusing on a different type of analysis of the star. Orrantia and Do led the team that studied the carbon content of the star, which turned out to be so low that it was undetectable.
“The star has so little carbon that it suggests an early sprinkling of cosmic dust is responsible for making it,” said Ji. “This formation pathway has only been seen once before.”
Contributing to such a discovery so early in their careers has helped Orrantia and Do decide to continue to pursue graduate careers in astronomy.
“To be able to actually contribute to something like this, it’s very exciting,” Do said.
“These students have discovered more than just the most pristine star.” said Juna Kollmeier, the Director of SDSS-V. “They have discovered their inalienable right to physics. Surveys like SDSS and Gaia make that possible for students of all ages everywhere on Earth and this example shows that there is still plenty of room for discovery.”
Journal
Nature Astronomy
Method of Research
Observational study
Subject of Research
Not applicable
Article Title
A nearly pristine star from the Large Magellanic Cloud
Article Publication Date
3-Apr-2026
Main image: students Ha Do (left) and Natalie Orrantia (right) observe the Ancient Immigrant star
Inset: The Irenee duPont telescope is the site of SDSS-V’s Southern sky component, which is rapidly surveying the cosmos. This telescope was reinvigorated with a new instrument suite and a new robotic focal plane to enable SDSS-V (left hand photo).
Credit
Main image: Ha Do (University of Chicago); Inset: SDSS Collaboration
Found: Most pristine star in the universe
An ancient immigrant: SDSS J0715-7334—which exists about 80,000 light-years from Earth—was born elsewhere and got pulled into our Milky Way galaxy over time
image:
An ancient immigrant: an artist's conception (not to scale) of the red giant SDSS J0915-7334, which was born near the Large Magellanic Cloud and has now journeyed to reside in the Milky Way.
view moreCredit: Navid Marvi/Carnegie Science
Pasadena, CA—An unusual team of astronomers used Sloan Digital Sky Survey-V (SDSS-V) data and observations on the Magellan telescopes at Carnegie Science’s Las Campanas Observatory in Chile to discover the most pristine star in the known universe, called SDSS J0715-7334. Their work is published in Nature Astronomy.
Led by the University of Chicago’s Alexander Ji—a former Carnegie Observatories postdoctoral fellow—and including Carnegie astrophysicist Juna Kollmeier—who leads SDSS, now in its fifth generation—the research team identified a star from just the second generation of celestial objects in the cosmos, which formed just a few billion years after the universe began.
“These pristine stars are windows into the dawn of stars and galaxies in the universe,” Ji explained. Several of his and Kollmeier’s co-authors on the paper are undergraduate students from UChicago, whom Ji brought to Las Campanas on an observing trip for spring break last year. “My first visit to LCO is where I really fell in love with astronomy, and it was special to share such a formative experience with my students.”
The Big Bang birthed the universe as a hot murky soup of energetic particles. Over time, as this material expanded, it began to cool and coalesce into neutral hydrogen gas. Some patches were denser than others and, after a few hundred million years, their gravity overcame the universe’s outward trajectory and the material collapsed inward. This became the first generation of stars, which were formed from just pristine hydrogen and helium.
These stars burned hot and died young, but not before producing new elements in their stellar forges, which were strewn outward into the cosmos by their end-of-life explosions. And from this detritus, new stars were born, which now comprised a wider array of elements than their predecessors.
“All of the heavier elements in the universe, which astronomers call metals, were produced by stellar processes—from fusion reactions occurring within stars to supernovae explosions to collisions between very dense stars,” said Ji. “So, finding a star with very little metal content in it told this group of students that they’d come across something very special.”
Astronomers like Ji and Kollmeier are interested in finding ancient stars from the second and third generation after the universe first developed structure. This would reveal how star formation has changed over the ensuing eons.
“We have to look in our cosmic backyard to find these objects, because we can’t yet observe individual stars at the dawn of star formation. Since these stars are rare, surveys like SDSS-V are designed to have the statistical power to find these needles in the stellar haystack and test our theories of star formation and explosion,” explained Kollmeier.
Sloan Digital Sky Survey has been one of the most successful and influential surveys in the history of astronomy and its fifth generation, which Kollmeier leads, takes millions of optical and infrared spectra, across the entire sky. This pioneering effort deploys both the du Pont telescope at Las Campanas in the Southern Hemisphere and the Apache Point Observatory in New Mexico in the Northern Hemisphere.
The wealth of SDSS-V data enabled Ji and his students to identify stars with very few heavy elements. Then, at Las Campanas, they used the state-of-the-art Magellan telescopes to take high-resolution spectra of these candidates. Amazingly, the magic occurred in the wee hours of the morning on their first Magellan observing run and SDSS J0715-7334 was confirmed as the new gold-standard of stellar purity.
“The ecosystem of telescopes at Las Campanas was critical to nearly every aspect of this breakthrough work, from the du Pont data collected as part of SDSS-V’s Milky Way mapping efforts to the Magellan observations that showed exactly how special SDSS J0715-7334 really is,” said Michael Blanton, Director and Crawford H. Greenewalt Chair of the Carnegie Science Observatories.
Las Campanas is home to four Carnegie telescopes, and this project made spectacular use of two of them, showcasing how innovations in instrumentation can drive discovery throughout a telescope’s life.
This interconnectedness is driven home by Ji and the student’s itinerary at Las Campanas. The night of their arrival they visited the du Pont telescope to see SDSS-V observers hard at work taking new data that will be added to the project’s enormous volume of resources for amateur and professional astronomers. The very next evening, they made their own observations on the Magellan Clay telescope.
Luckily, after the discovery, Ji was able to reconfigure the rest of the semester so that
the students could spend their time digging deeper into their find—a real-world example for his students of how the ability to pivot is critical to making scientific breakthroughs.
“When I was an undergraduate, I greatly preferred doing research to taking classes. I’m delighted that Alex’s course was transformed into a curriculum of discovery and I’d like to ensure surveys like SDSS-V and Gaia have the power to make that the norm and not the exception,” Kollmeier said.
Deeper analysis of the Magellan spectra showed that it has less than 0.005 percent of the Sun’s metal content. It is twice as metal-poor as the previous record holder for most-pristine star and has particularly low abundances of iron and carbon. In fact, it is 40 times more metal-poor than the most iron-poor known star.
By incorporating data from the European Space Agency’s Gaia mission, the students were also able to determine that SDSS J0715-7334—which exists about 80,000 light-years from Earth—was born elsewhere and got pulled into our Milky Way galaxy over time.
“Training the next generation of astronomers is critical to the future of our field. And building excitement about the practice of science by undertaking projects like this is a great way to ensure that curious-minded young learners can see themselves in astrophysics,” Ji concluded. “My time as a postdoc at Carnegie was pivotal to my professional growth and I am thrilled that I was able to pay that experience forward by bringing my students to Las Campanas.”
Students from University of Chicago professor Alexander Ji’s “Field Course in Astrophysics” class pose in front of the Magellan Clay telescope at Carnegie Science’s Las Campanas Observatory in Chile. They are using their bodies to spell MIKE, referencing the Magellan Inamori Kyocera Echelle (MIKE) spectrograph instrument that they used on the telescope to make their breakthrough discovery. From left to right: Hillary Diane Andales, Pierre Thibodeaux, Ha Do, Natalie Orrantia, Rithika Tudmilla, Selenna Mejias-Torres, Zhongyuan Zhang and Alex Ji.
Credit
Zhongyuan Zhang
Journal
Nature Astronomy
Method of Research
Observational study
Subject of Research
Not applicable
Article Title
A nearly pristine star from the Large Magellanic Cloud
Article Publication Date
3-Apr-2026
How did this get made? Giant planet orbits small star
Carnegie Institution for Science
image:
An artist’s conception of the gas giant planet TOI-5205 b orbiting a small, cool red dwarf star.
view moreCredit: Katherine Cain, Carnegie Science.
Washington, D.C.—Observations of the highly unusual—sometimes called “forbidden”—exoplanet TOI-5205 b taken by JWST suggest the giant planet’s atmosphere has fewer heavier elements than its host star. These findings have implications for our understanding of the giant planet formation process that occurs early in a star’s lifespan.
Published this week by The Astronomical Journal, these findings represent the collaborative work of an international team of astronomers led by NASA Goddard Space Flight Center’s Caleb Cañas and including Carnegie Science’s Shubham Kanodia.
TOI 5205 b is a Jupiter-sized planet orbiting a star that is itself about four times the size of Jupiter and about 40 percent the mass of the Sun. When it passes in front of its host star—a phenomenon astronomers call a “transit”—the planet blocks about six percent of its light. By observing this transit with telescope instruments called spectrographs that split the light into its constituent colors, astronomers can try to decipher the planet’s atmospheric makeup and learn more about its history and relationship with its host star.
Planets are born from the rotating disk of gas and dust that surrounds a star in its youth. While it is commonly accepted that giant planets form in these cloudy disks that result from the birth of the host star, the existence of massive planets like TOI-5205b orbiting cool stars at close distances raises many questions about this process.
To shed more light on this, Kanodia, Cañas and Jessica Libby-Roberts of the University of Tampa are leading the largest JWST Cycle 2 exoplanet program, Red Dwarfs and the Seven Giants, which was designed to study unlikely worlds like TOI-5205 b—sometimes called GEMS (for giant exoplanets around M dwarf stars).
Back in 2023, Kanodia led the effort that confirmed TOI-5205 b’s existence, following up on information from NASA’s Transiting Exoplanet Survey Satellite (TESS), which first identified it as a planetary candidate. Now, he’s co-leading the team that made the first observations of its atmospheric composition.
Their observations of three transits of TOI5205-b revealed something that the astronomers couldn’t easily explain. They were surprised to see that the planet’s atmosphere has a lower concentration of heavy elements—relative to hydrogen—than a gas giant planet in our own Solar System like Jupiter. It even has a lower metallicity than its own host star. This makes it stand out among all the giant planets that have been studied to date.
Additionally, although less shocking, the transits revealed methane (CH₄) and hydrogen sulfide (H₂S) in TOI-5205-b’s atmosphere.
To contextualize their findings, team members Simon Muller and Ravit Helled at University of Zurich deployed sophisticated models of planetary interiors to predict that the entirety of TOI5205-b’s composition is about 100 times more metal rich than its atmosphere, as measured by the transits.
“We observed much lower metallicity than our models predicted for the planet’s bulk composition, which is calculated from measurements of a planet’s mass and radius. This suggests that its heavy elements migrated inward during formation and now its interior and atmosphere are not mixing,” Kanodia explained. “In summary, these results suggest a very carbon-rich, oxygen-poor planetary atmosphere.”
The research is part of the GEMS Survey, a program dedicated to studying transiting giant planets around M-dwarf stars to understand their formation, structure, and atmospheres. The research group also includes Carnegie astronomers Peter Gao, Johanna Teske, and Nicole Wallack, as well as recently departed Carnegie postdoctoral fellow Anjali Piette, now on faculty at University of Birmingham.
Other co-authors are: Jacob Lustig-Yaeger, Erin May, and Kevin Stevenson of the Applied Physics Laboratory at Johns Hopkins University; Shang-Min Tsai of the Academia Sinica Institute of Astronomy and Astrophysics; Dana Louie of Catholic University; Giannina Guzmán Caloca of the University of Maryland; Kevin Hardegree-Ullman of Caltech; Knicole Colón of the NASA Goddard Space Flight Center; Ian Czekala of University of St. Andrews; Megan Delamer and Suvrath Mahadevan of Penn State University; Andrea Lin and Te Han of the University of California Irvine; Joe Ninan of the Tata Institute of Fundamental Research; and Guðmundur Stefánsson of the University of Amsterdam.
The researchers worked together to correct for the effects that starspots on TOI-5205 b’s host star had on their data. Because the star is heavily spotted, it left an imprint on the data—brightening some wavelengths and masking potential signatures in the atmosphere. Wallack and Kanodia are now validating this method in a more-recent JWST project in the same planetary system, which will prove useful for future investigations of this and other planets around active stars.
Journal
The Astronomical Journal
Method of Research
Observational study
Subject of Research
Not applicable
Article Title
GEMS JWST: Transmission Spectroscopy of TOI-5205b Reveals Significant Stellar Contamination and a Metal-poor Atmosphere
Astronomers thought the early universe was full of hydrogen. Now they’ve found it.
A new study has now increased the known number of hydrogen gas halos by a factor of ten: from roughly 3,000 to over 33,000.
University of Texas at Austin
image:
An enormous halo of hydrogen gas found in Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) data and superimposed over its location as seen in deep imaging from the James Webb Space Telescope (JWST). Present 11.3 billion years ago, this system glows from the combined light of many galaxies within it, with the brightest region represented in red. Using data from HETDEX, astronomers have increased the known number of these haloes by more than a factor of ten - from roughly 3,000 to over 33,000.
view moreCredit: Credit: Erin Mentuch Cooper (HETDEX), JWST image: NASA, ESA, CSA, STScI.
Astronomers using data from the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) have discovered tens of thousands of gigantic hydrogen gas halos, called “Lyman-alpha nebulae,” surrounding galaxies 10 billion to 12 billion years ago. Known as Cosmic Noon, this is an epoch in the early universe when galaxies were growing their fastest. To spur this growth, they would have needed access to vast reservoirs of hydrogen gas, a key building block for stars. However, until recently, astronomers had only found a handful of these essential structures.
A new study published in The Astrophysical Journal has now increased the known number of hydrogen gas halos by a factor of ten: from roughly 3,000 to over 33,000. This confirms suspicions that they are not rare curiosities. The study also increases the range of known sizes, providing a more representative sample for astronomers to study as they continue to tease out the origin and evolution of the first galaxies.
“We’ve been analyzing the same handful of objects for the past 20 or so years,” said Erin Mentuch Cooper, HETDEX data manager and lead author on the study. “HETDEX is letting us find many more of these halos and measure their shapes and sizes. It has really allowed us to create an amazing statistical catalogue.”
Hydrogen gas is notoriously hard to detect because it doesn’t generate its own light. However, if it’s near an object that’s throwing off a lot of energy – say, a galaxy or group of galaxies full of UV-emitting stars – that energy can cause the hydrogen to glow. To detect this, you need to dedicate a lot of time on precise instruments, which are often in high demand.
While previous astronomical surveys have found some of these halos, their instruments were only able to pick up on the brightest, most extreme examples. And targeted observations of early galaxies are usually so zoomed in that they cut off all but the smallest halos. As a result, everything in between the little guys and the big honkers has remained elusive.
Observations from HETDEX are starting to fill in this gap. Using the Hobby-Eberly Telescope at McDonald Observatory, it is charting the position of over one million galaxies in its quest to understand dark energy. “We’ve captured nearly half a petabyte of data on not only these galaxies but the regions in between,” said Karl Gebhardt, HETDEX principal investigator, chair of The University of Texas at Austin’s astronomy department, and co-author on the paper. “Our observations cover a region of the sky measuring over 2,000 full Moons. The scope is enormous and unprecedented.”
“The Hobby-Eberly Telescope is one of the largest in the world,” added Dustin Davis, a postdoctoral fellow at UT Austin, a HETDEX scientist, and co-author on the study. “And the instrument HETDEX uses produces 100,000 spectra in each observation. So, we have huge amounts of data and there are all kinds of neat, fun, weird things waiting for us to find.”
The newly revealed halos measure from tens of thousands to hundreds of thousands of light years across. Some are as simple as a football-shaped cloud surrounding a single galaxy. Others are sprawling, irregular blobs containing multiple galaxies. “Those are the fun ones,” said Mentuch Cooper. “They look like giant amoebas with tendrils extending into space.”
To find them, the team selected the 70,000 brightest of the over 1.6 million early galaxies that have been identified by HETDEX so far. With the help of supercomputers at the Texas Advanced Computing Center, they looked to see how many of these showed evidence of a surrounding halo: a compact central region of hydrogen and a thinner cloud extending beyond it.
Nearly half did. What’s more, this fraction is likely an underestimate, explained Mentuch Cooper. “We suspect the faintest systems simply aren’t bright enough to fully reveal how large they are.”
The team hopes their discovery will help others study the early universe: how its structures evolved, the distribution of matter, the movement of objects, and more. With 33,000 halos to study, the problem will no longer be where to find them, but which one to choose.
“There are various models for galaxies in this epoch that largely work and seem to make sense, but there are gaps and holes,” explained Davis. “Now we can focus in on individual halos and see at a greater detail the physics and mechanics of what's going on. And then we can fix or throw out the models and try again.”
Journal
The Astrophysical Journal
Subject of Research
Not applicable
Article Title
Lyα Nebulae in HETDEX: The Largest Statistical Census Bridging Lyα Halos and Blobs across Cosmic Noon
Did impacts from meteors help start life on Earth?
Research synthesized by a recent graduate suggests vents generated from the impacts of space rocks may have enabled suitable environments for the first living cells
image:
Scientists looking for sources that generated life on Earth are considering hydrothermal vents of different types, from vents found in the deep sea to others created by meteor impacts.
view moreCredit: Richard Lutz/Rutgers University
Meteor impacts may have helped spark life on Earth, creating hot, chemical-rich environments where the first living cells could take shape, according to research integrated by a recent Rutgers University graduate.
“No one knows, from a scientific perspective, how life could have been formed from an early Earth that had no life,” said Shea Cinquemani, who earned her bachelor’s degree in marine biology and fisheries management from the Rutgers School of Environmental and Biological Sciences in May 2025. “How does something come from nothing?”
Cinquemani is the lead author of a scientific review, published in the peer-reviewed Journal of Marine Science and Engineering, examining where life may have first formed on Earth. The paper focuses on hydrothermal vents, places where hot, mineral-rich water flows through rock and emerges into surrounding water, creating the chemical conditions and energy gradients needed for complex reactions.
Her research points to hydrothermal systems created by meteor impacts as a potentially critical and underappreciated setting for the origin of life, strengthening the case beyond conventional deep-sea vent theories. Cinquemani said such systems would have been widespread on early Earth, making them especially compelling environments for life to begin.
The paper, co-authored with Rutgers oceanographer Richard Lutz, marks a rare achievement for a recent undergraduate whose work began as a class assignment and was transformed into a publication in a highly respected scientific journal.
“It’s amazing,” Lutz said. “You often have undergraduates that are part of papers –
faculty choose undergraduates all the time to work on papers and projects. But for an undergraduate to be the lead author is a huge deal.”
The project started in the spring of Cinquemani’s senior year in a course called “Hydrothermal Vents,” taught by Lutz, a Distinguished Professor in the Department of Marine and Coastal Sciences. Cinquemani’s assignment was to examine whether hydrothermal vents on Mars could have been harbingers of life there.
“I was like, ‘I know nothing about this topic,’” she said. “Thinking about the origins of biology on another planet was like, whoa. Not sure how I’m going to do this.” The topic went beyond her usual comfort zone of biology and extended into chemistry, physics and geology, she said.
Cinquemani expanded the assignment after graduation into a full scientific review of both impact-generated and deep-sea vent systems, which was accepted after what Lutz described as a demanding peer-review evaluation.
“I have never seen such a rigorous review process,” Lutz said. “There were 15 pages of comments and five different rounds of reviews. She had the patience and perseverance, and the paper turned out magnificently.”
Deep-sea hydrothermal vents have long been considered a possible birthplace of life. Discovered in the deep ocean in the late 1970s, these systems host entire ecosystems that thrive without sunlight. Instead of photosynthesis, microbes use chemical energy from compounds released by vent fluids, such as hydrogen sulfide, in a process known as chemosynthesis.
Some deep-sea vents are powered by heat from the Earth’s interior near volcanic activity while others are driven by chemical reactions between water and rock that generate heat without magma. This heat facilitates chemical processes and provides a warm oasis in the otherwise barren seafloor of the deep ocean.
Cinquemani’s paper places more focus on a different category that has recently begun gaining attention: hydrothermal systems created by meteor impacts.
When a large meteor strikes Earth, the impact generates intense heat and melts surrounding rock. As the area cools and water fills the crater, a hot, mineral-rich environment can form, similar in some ways to deep-sea vents.
“You have a lake surrounding a very, very warm center,” Cinquemani said. “And now you get a hydrothermal vent system, just like in the deep sea, but made by the heat from an impact.”
To explore how these systems might support life, she examined research on three well-studied crater sites that span vastly different periods of Earth’s history. The oldest is the Chicxulub impact structure beneath Mexico’s Yucatán Peninsula, formed about 65 million years ago and later shown to have hosted a long-lived hydrothermal system. Next is the Haughton impact structure in the Canadian Arctic, formed about 31 million years ago. The youngest is Lonar Lake in India, created about 50,000 years ago, where the crater still contains water and offers clues about how these systems evolve over time.
These impact-generated systems may last thousands to tens of thousands of years, giving simple molecules time to form more complex structures that could lead to life.
Scientists say such environments may have been especially important on early Earth, which experienced frequent asteroid impacts. In that sense, events often seen as destructive also may have helped create the conditions for life.
The idea builds on decades of research into deep-sea vents while expanding the search for life’s origins into new territory.
Lutz helped explore these deep-sea environments several decades ago when they were still a scientific mystery. As a young postdoctoral researcher, he joined the first biological expeditions
Those dives helped open a new field of research and shaped scientists’ understanding of how life can exist in extreme environments without sunlight.
“We have talked for many years about the possibility that life may have originated at deep-sea hydrothermal vents,” Lutz said.
Cinquemani’s work brings together those long-standing ideas with newer evidence that impact-generated systems also could play a role and may in some cases offer favorable conditions for early chemical reactions.
The implications extend beyond Earth. Hydrothermal activity is thought to exist on the ocean floors of icy moons such as Jupiter’s Europa and Saturn’s Enceladus, and may have existed in impact craters on young Mars. If these environments on Earth can support the chemistry of life, they could become key targets in the search for life elsewhere.
For Cinquemani, the work is driven by curiosity.
“Humans are insanely curious beings,” said Cinquemani, who works as a technician at Rutgers’ New Jersey Aquaculture Innovation Center in Cape May, N.J., where she supports aquaculture research while preparing to pursue advanced study in marine science. “We question everything. We may never know exactly how we began, but we can try our best to understand how things might have occurred.”
Explore more of the ways Rutgers research is shaping the future.
Journal
Journal of Marine Science and Engineering
Method of Research
Literature review
Subject of Research
Not applicable
Article Title
Deep-Sea Hydrothermal Vent and Impact-Generated Hydrothermal Vent Systems: Insights into the Origin of Life
The depths of Neptune and Uranus may be “superionic”
image:
Illustration of the predicted hexagonal carbon hydride compound under Neptune-like interior conditions. In this structure, carbon forms the outer spiral chains (yellow) and hydrogen forms the inner spiral chains (blue), consistent with the quasi-one-dimensional superionic behavior identified in first-principles simulations.
view moreCredit: Cong Liu
Washington, DC—The interiors of ice giant planets like Uranus and Neptune could be home to a previously unknown state of matter, according to new computational simulations by Carnegie’s Cong Liu and Ronald Cohen.
Their work, published in Nature Communications, predicts that a quasi-one-dimensional superionic state of carbon hydride exists under the extreme pressures and temperatures found deep inside these outer Solar System bodies.
More than 6,000 exoplanets have been discovered. As this number grows, astronomers, planetary scientists, and Earth scientists are crossing disciplinary boundaries—combining observation, experimentation, and theory—to define and probe the factors that help us understand the dynamic processes that shape them, including the generation of magnetic fields.
As such, interest has grown in understanding the processes that are occurring deep beneath the surfaces of planets and moons in our own Solar System, which can inform our understanding of planetary dynamics, and even planetary habitability in more-distant neighborhoods.
Measurements of Uranus and Neptune’s densities indicate that the interiors of these giant planets contain intermediate layers of unconventional “hot ices,” which exist below their hydrogen and helium atmospheric envelopes and above their rocky cores. These layers are believed to be composed of water (H2O), methane (CH4), and ammonia (NH4), but due to the extreme conditions, it is thought that exotic phases would emerge.
The physics in these high-pressure, high-temperature regions can give rise to unconventional states of matter, which is why theorists and experimentalists attempt to predict and recreate what would be found there.
Using high-performance computing and machine-learning, Liu and Cohen performed fundamental quantum physics simulations of carbon hydride (CH) under pressures ranging from nearly 5 million to nearly 30 million times atmospheric pressure (500 to 3,000 gigapascals) and at temperatures ranging from 6,740 to 10,340 degrees Fahrenheit (4,000 to 6,000 Kelvin).
Their tools predicted the emergence of an ordered hexagonal framework in which hydrogen atoms move along spiral pathways, creating a quasi-one-dimensional superionic state.
Superionic materials occupy an unusual middle ground between solids and liquids—one type of atom remains arranged in a crystalline framework and another becomes mobile.
“This newly predicted carbon–hydrogen phase is particularly striking because the atomic motion is not fully three-dimensional,” Cohen explained. “Instead, hydrogen moves preferentially along well-defined helical pathways embedded within an ordered carbon structure.”
This directionality of this movement has important implications for how heat and electricity move through planetary interiors. Such behavior could influence interior energy redistribution, electrical conductivity, and possibly the interpretation of magnetic-field generation in ice giants.
Their findings also expand our understanding of the behavior of simple compounds under extreme conditions, suggesting that even simple systems can organize into unexpectedly complex phases.
“Carbon and hydrogen are among the most abundant elements in planetary materials, yet their combined behavior at giant-planet conditions remains far from fully understood,” Liu concluded.
Beyond planetary interiors, the ability to identify strongly directional emergent phenomena in condensed matter could have ramifications for materials science and engineering.
Journal
Nature Communications
Article Title
Prediction of thermally driven quasi-1D superionic states in carbon hydride under giant planetary conditions
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