It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Wednesday, January 29, 2025
SPACE/COSMOS
Dust from asteroid Bennu shows: Building blocks of life and possible habitats were widespread in our solar system
International study analyzes material from asteroid Bennu that was brought to Earth by NASA's OSIRIS-REx space mission
Cosmochemist Professor Frank Brenker shows three grains of a meteorite that the Goethe University team used to test research methods in advance. The quantity and type corresponded to the material from the asteroid Bennu.
FRANKFURT. It took two years for NASA’s OSIRIS-REx space probe to return from asteroid Bennu before dropping off a small capsule as it flew past Earth, which was then recovered in the desert of the U.S. state of Utah on September 24, 2023. Its contents: 122 grams of dust and rock from asteroid Bennu. The probe had collected this sample from the surface of the 500-metre agglomerate of unconsolidated material in a touch-and-go maneuver that took just seconds. Since the capsule protected the sample from the effects of the atmosphere, it could be analyzed in its original state by a large team of scientists from more than 40 institutions around the world.
The partners in Germany were geoscientists Dr. Sheri Singerling, Dr. Beverley Tkalcec and Prof. Frank Brenker from Goethe University Frankfurt. They examined barely visible grains of Bennu using the transmission electron microscope of the Schwiete Cosmochemistry Laboratory, set up at Goethe University only a year ago with the support of the Dr. Rolf M. Schwiete Foundation, the German Research Foundation and the State of Hesse. Its goal: to reconstruct the processes that took place on Bennu’s protoplanetary parent body more than four billion years ago and ultimately led to the formation of the minerals that exist today. The Frankfurt scientists succeeded in doing this by analyzing the mineral grains’ exact structure and determining their chemical composition at the same time. They also carried out trace element tomography of the samples at accelerators such as DESY (Deutsches Elektronen-Synchrotron) in Hamburg.
“Together with our international partner teams, we have been able to detect a large proportion of the minerals that are formed when salty, liquid water – known as brine – evaporates more and more and the minerals are precipitated in the order of their solubility,” explains Dr. Sheri Singerling, who manages the Schwiete Cosmo Lab. In technical terms, the rocks that form from such precipitation cascades are called evaporites. They have been found on Earth in dried-out salt lakes, for example.
“Other teams have found various precursors of biomolecules such as numerous amino acids in the Bennu samples,” reports Prof. Frank Brenker. “This means that Bennu’s parent body had some known building blocks for biomolecules, water and – at least for a certain time – energy to keep the water liquid.” However, the break-up of Bennu’s parent body interrupted all processes very early on and the traces that have now been discovered were preserved for more than 4.5 billion years.
“Other celestial bodies such as Saturn's moon Enceladus, or the dwarf planet Ceres have been able to evolve since then and are still very likely to have liquid oceans or at least remnants of them under their ice shells,” says Brenker. “Since this means that they have a potential habitat, the search for simple life that could have evolved in such an environment is a focus of future missions and sample studies.”
OSIRIS-REx NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provided overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator. The university leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Littleton, Colorado, built the spacecraft and provided flight operations.
Background information Daniel P. Glavin et al.: Abundant ammonia and nitrogen-rich soluble organic matter in samples from asteroid (101955) Bennu Nature Astronomy (2025) https://doi.org/10.1038/s41550-024-02472-9
Captions: 1) Studies of the smallest amounts of material: Cosmochemist Professor Frank Brenker shows three grains of a meteorite that the Goethe University team used to test research methods in advance. The quantity and type corresponded to the material from the asteroid Bennu. Photo: Uwe Dettmar for Goethe University. 2) A few specks of dust: The samples analyzed in the transmission electron microscope of the Schwiete Cosmo Lab at Goethe University are barely visible. Arrows indicate three of the samples. Photo without arrows: NASA 3) In the lab: Dr. Sheri Singerling inserts a sample carrier into the transmission electron microscope of the Schwiete Cosmo Lab. Photo: Uwe Dettmar for Goethe University 4) In the lab (2): Dr. Sheri Singerling analyzing the TEM images of the material from Bennu. Photo: Uwe Dettmar for Goethe University
The samples analyzed in the transmission electron microscope of the Schwiete Cosmo Lab at Goethe University are barely visible. Arrows indicate three of the samples.
Credit
Photo without arrows: NASA
In the Schwiete Cosmo Lab
Dr. Sheri Singerling inserts a sample carrier into the transmission electron microscope of the Schwiete Cosmo Lab at Goethe University Frankfurt
Dr. Sheri Singerling, Goethe University, analyzing the TEM images of the material from Bennu.
An evaporite sequence from ancient brine recorded in Bennu samples
Article Publication Date
29-Jan-2025
Berkeley Lab helps explore mysteries of Asteroid Bennu
The Advanced Light Source and Molecular Foundry provided powerful tools to study asteroid samples returned by NASA’s OSIRIS-REx mission. Researchers found a telltale set of salts formed by evaporation that illuminate Bennu’s watery past
During the past year, there’s been an unusual set of samples at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab): material gathered from the 4.5-billion-year-old asteroid Bennu when it was roughly 200 million miles from Earth.
Berkeley Lab is one of more than 40 institutions investigating Bennu’s chemical makeup to better understand how our solar system and planets evolved. In a new study published today in the journal Nature, researchers found evidence that Bennu comes from an ancient wet world, with some material from the coldest regions of the solar system, likely beyond the orbit of Saturn.
The asteroid contained a set of salty mineral deposits that formed in an exact sequence when a brine evaporated, leaving clues about the type of water that flowed billions of years ago. Brines could be a productive broth for cooking up some of the key ingredients of life, and the same type of minerals are found in dried-up lake beds on Earth (such as Searles Lake in California) and have been observed on Jupiter’s moon Europa and Saturn’s moon Enceladus.
“It’s an amazing privilege to be able to study asteroid material, direct from space,” said Matthew Marcus, a Berkeley Lab scientist who runs the Advanced Light Source (ALS) beamline where some of the samples were studied and who wrote one of the programs used to analyze their chemical composition. "We have highly specialized instruments that can tell us what Bennu is made of and help reveal its history."
The samples from Bennu were gathered by NASA’s OSIRIS-REx mission, the first U.S. mission to return samples from an asteroid. The mission returned nearly 122 grams of material from Bennu – the largest sample ever captured in space and returned to Earth from an extraterrestrial body beyond the Moon.
Marcus teamed up with Scott Sandford from NASA Ames Research Center and Zack Gainsforth from the UC Berkeley Space Sciences Laboratory to study the Bennu sample using scanning transmission X-ray microscopy (STXM) at the ALS. By varying the energy of the X-rays, they were able to determine the presence (or absence) of specific chemical bonds at the nanometer scale and map out the different chemicals found in the asteroid. The science team discovered that some of the last salts to evaporate from the brine were mixed into the rock at the finest levels.
“This sort of information provides us with important clues about the processes, environments, and timing that formed the samples,” Sandford said. “Understanding these samples is important, since they represent the types of materials that were likely seeded on the surface of the early Earth and may have played a role in the origins and early evolution of life.”
At Berkeley Lab’s Molecular Foundry, researchers used a beam of electrons to image the same Bennu samples with transmission electron microscopy (TEM). The Foundry also helped prepare the samples for the experiments run at the ALS. Experts used an ion beam to carve out microscopic sections of the material that are about a thousand times thinner than a sheet of paper.
“Being able to examine the same exact atoms using both STXM and TEM removed many of the uncertainties in interpreting our data,” Gainsforth said. “We were able to confirm that we really were seeing a ubiquitous phase formed by evaporation. It took a lot of work to get Bennu to give up its secrets, but we are delighted with the final result.”
This is not the first time the ALS and Molecular Foundry have studied material from space. Researchers also used the two facilities to investigate samples from the asteroid Ryugu, building up our understanding of our early solar system. And there’s still more to come, with additional studies of Bennu at both the STXM and infrared beamlines at the ALS planned for the coming year.
Berkeley Lab researchers also contributed to a second paper published today in Nature Astronomy that analyzed organic materials found on the asteroid. Within the Bennu sample, the science team identified 14 of the 20 amino acids that life on Earth uses to build proteins. They also found all five nucleobases, the ring-shaped molecules that form DNA and RNA, as well as ammonia, which on Earth might have helped spark the emergence of early life.
The results support the idea that asteroids like Bennu may have delivered water and essential chemical building blocks of life to Earth in the distant past. Based on the similarities between asteroid Bennu and the icy dwarf planets and moons of our outer solar system, these potential ingredients for life could be widespread.
NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provided overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator. The university leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Littleton, Colorado, built the spacecraft and provided flight operations.
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Pristine asteroid samples reveal secrets of the ancient solar system Researchers have gained an unprecedented glimpse into the early history of our solar system through some of the most well-preserved asteroid samples ever collected, potentially transforming our understanding of planetary formation and the origins of life
Curtin University
Curtin University researchers have gained an unprecedented glimpse into the early history of our solar system through some of the most well-preserved asteroid samples ever collected, potentially transforming our understanding of planetary formation and the origins of life.
Experts from Curtin’s School of Earth and Planetary Sciences were selected to be amongst the first in the world to inspect samples collected during NASA’s seven-year, OSIRIS-REx mission to the ancient asteroid Bennu.
Asteroid Bennu is thought to be made of rubble fragments from a 4.5-billion-year-old parent body, containing materials that originated beyond Saturn, which was destroyed long ago in a collision with another object.
The OSIRIS-REx sample analysis team identified a variety of salts, including sodium carbonates, phosphates, sulphates, and chlorides.
“We were surprised to identify the mineral halite, which is sodium chloride — exactly the same salt that you might put on your chips,” Associate Professor Timms said.
“The minerals we found form from evaporation of brines – a bit like salt deposits forming in the salt lakes that we have in Australia and around the world.
“By comparing with mineral sequences from salt lakes on Earth, we can start to envisage what it was like on the parent body of asteroid Bennu, providing insight into ancient cosmic water activity.”
Evaporite minerals and brines are known to help organic molecules develop on Earth.
“A briny, carbon-rich environment on Bennu’s parent body was probably suitable for assembling the building blocks of life,” Associate Professor Timms said.
The key to the new discovery was the pristine condition of the samples.
Many of the salts present degrade quickly when exposed to the atmosphere, however the samples collected on the OSIRIS-REx mission were sealed and purged with nitrogen once on Earth to prevent contamination.
NASA chose Curtin to perform early analysis on the samples — the largest ever retrieved from a world beyond the Moon — due to the globally renowned John de Laeter Centre’s world-leading expertise and facilities.
Centre Director Associate Professor Will Rickard said the facility houses more than $50 million in advanced analytical instruments.
“The Centre is one of the few places in the world which could verify if the salts were in fact extraterrestrial in origin or if they had been contaminated by elements from Earth,” Associate Professor Rickard said.
“Our specialised facilities at Curtin allowed us to maintain the pristine condition of the samples, which meant when we discovered the salts were extraterrestrial and unaltered, we knew it was an important finding because these samples preserve evidence of some of the earliest phenomena of the solar system.”
The findings from returned samples of asteroid Bennu may provide researchers insight into what happens on distant icy bodies in our solar system, such as Saturn’s moon Enceladus and the dwarf planet Ceres in the asteroid belt.
“Both Enceladus and Ceres have subsurface brine oceans,” Associate Professor Timms said.
“Even though asteroid Bennu has no life, the question is could other icy bodies harbour life?”
NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provided overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx.
Dante Lauretta of the University of Arizona, Tucson, is the principal investigator.
The university leads the science team and the mission’s science observation planning and data processing.
Lockheed Martin Space in Littleton, Colorado, built the spacecraft and provided flight operations.
‘An evaporite sequence from ancient brine recorded in Bennu samples’ was published in Nature.
In this video frame, Jason Dworkin holds up a vial that contains part of the sample from asteroid Bennu delivered to Earth by NASA’s OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security – Regolith Explorer) mission in 2023. Dworkin is the mission’s project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
Studies of rock and dust from asteroid Bennu delivered to Earth by NASA’s OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification and Security–Regolith Explorer) spacecraft have revealed molecules that, on our planet, are key to life, as well as a history of saltwater that could have served as the “broth” for these compounds to interact and combine.
The findings do not show evidence for life itself, but they do suggest the conditions necessary for the emergence of life were widespread across the early solar system, increasing the odds life could have formed on other planets and moons.
“NASA’s OSIRIS-REx mission already is rewriting the textbook on what we understand about the beginnings of our solar system,” said Nicky Fox, associate administrator, Science Mission Directorate at NASA Headquarters in Washington. “Asteroids provide a time capsule into our home planet’s history, and Bennu’s samples are pivotal in our understanding of what ingredients in our solar system existed before life started on Earth.”
In research papers published Wednesday in the journals Nature and Nature Astronomy, scientists from NASA and other institutions shared results of the first in-depth analyses of the minerals and molecules in the Bennu samples, which OSIRIS-REx delivered to Earth in 2023.
Detailed in the Nature Astronomy paper, among the most compelling detections were amino acids – 14 of the 20 that life on Earth uses to make proteins – and all five nucleobases that life on Earth uses to store and transmit genetic instructions in more complex terrestrial biomolecules, such as DNA and RNA, including how to arrange amino acids into proteins.
Scientists also described exceptionally high abundances of ammonia in the Bennu samples. Ammonia is important to biology because it can react with formaldehyde, which also was detected in the samples, to form complex molecules, such as amino acids – given the right conditions. When amino acids link up into long chains, they make proteins, which go on to power nearly every biological function.
These building blocks for life detected in the Bennu samples have been found before in extraterrestrial rocks. However, identifying them in a pristine sample collected in space supports the idea that objects that formed far from the Sun could have been an important source of the raw precursor ingredients for life throughout the solar system.
“The clues we’re looking for are so minuscule and so easily destroyed or altered from exposure to Earth’s environment,” said Danny Glavin, a senior sample scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and co-lead author of the Nature Astronomy paper. “That’s why some of these new discoveries would not be possible without a sample-return mission, meticulous contamination-control measures, and careful curation and storage of this precious material from Bennu.”
While Glavin’s team analyzed the Bennu samples for hints of life-related compounds, their colleagues, led by Tim McCoy, curator of meteorites at the Smithsonian’s National Museum of Natural History in Washington, and Sara Russell, cosmic mineralogist at the Natural History Museum in London, looked for clues to the environment these molecules would have formed. Reporting in the journal Nature, scientists further describe evidence of an ancient environment well-suited to kickstart the chemistry of life.
Ranging from calcite to halite and sylvite, scientists identified traces of 11 minerals in the Bennu sample that form as water containing dissolved salts evaporates over long periods of time, leaving behind the salts as solid crystals.
Similar brines have been detected or suggested across the solar system, including at the dwarf planet Ceres and Saturn’s moon Enceladus.
Although scientists have previously detected several evaporites in meteorites that fall to Earth’s surface, they have never seen a complete set that preserves an evaporation process that could have lasted thousands of years or more. Some minerals found in Bennu, such as trona, were discovered for the first time in extraterrestrial samples.
“These papers really go hand in hand in trying to explain how life’s ingredients actually came together to make what we see on this aqueously altered asteroid,” said McCoy.
For all the answers the Bennu sample has provided, several questions remain. Many amino acids can be created in two mirror-image versions, like a pair of left and right hands. Life on Earth almost exclusively produces the left-handed variety, but the Bennu samples contain an equal mixture of both. This means that on early Earth, amino acids may have started out in an equal mixture, as well. The reason life “turned left” instead of right remains a mystery.
“OSIRIS-REx has been a highly successful mission,” said Jason Dworkin, OSIRIS-REx project scientist at NASA Goddard and co-lead author on the Nature Astronomy paper. “Data from OSIRIS-REx adds major brushstrokes to a picture of a solar system teeming with the potential for life. Why we, so far, only see life on Earth and not elsewhere, that’s the truly tantalizing question.”
NASA Goddard provided overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator. The university leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Littleton, Colorado, built the spacecraft and provided flight operations. NASA Goddard and KinetX Aerospace were responsible for navigating the OSIRIS-REx spacecraft. Curation for OSIRIS-REx takes place at NASA’s Johnson Space Center in Houston. International partnerships on this mission include the OSIRIS-REx Laser Altimeter instrument from CSA (Canadian Space Agency) and asteroid sample science collaboration with JAXA’s (Japan Aerospace Exploration Agency) Hayabusa2 mission. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.
For more information on the OSIRIS-REx mission, visit:
The origin of life is one of the deepest mysteries in science, but the clues to solving it have been buried by plate tectonics, the water cycle, and even life itself. For answers, scientists are looking beyond Earth to primitive asteroids like Bennu, the target of NASA’s daring OSIRIS-REx sample return mission. OSIRIS-REx gathered pristine material from Bennu in 2020 and delivered it to Earth in 2023. Now, rocks from Bennu are revealing a lost world from the dawn of the solar system, with the right conditions to foster the building blocks of life.
A mosaic image of asteroid Bennu, composed of 12 PolyCam images collected by the OSIRIS-REx spacecraft from a range of 24 kilometers. (NASA/Goddard/University of Arizona)
Japanese collaborators detected all five nucleobases — building blocks of DNA and RNA — in samples returned from asteroid Bennu by NASA’s OSIRIS-REx mission.
Asteroids, small airless bodies within the inner Solar System, are theorized to have contributed water and chemical building blocks of life to Earth billions of years ago. Although meteorites on Earth come from asteroids, the combination of exposure to moisture in the atmosphere and to an uncontrolled biosphere means that interpreting the data from them is challenging. Pristine samples collected from asteroids in space would be the ideal candidates, and successful sample collection missions have only been achieved by two countries: Japan (Hayabusa and Hayabusa2) and the United States (OSIRIS-REx).
NASA’s OSIRIS-REx mission returned 121.6 grams of sample from asteroid (101955) Bennu in September 2023—the largest sample ever returned to Earth. Now, an international team of OSIRIS-REx sample analysis team scientists, led by Dr. Daniel Glavin and Dr. Jason Dworkin at the NASA Goddard Space Flight Center, has reported the discovery of ammonia and nitrogen-rich soluble organic matter in these samples. The findings were published in the journal Nature Astronomy. Among the findings, the Japanese contributors detected all five nitrogenous bases, molecules required for building DNA and RNA, supporting the theory that asteroids could have brought the building blocks of life to Earth.
The Bennu samples from NASA were handled under nitrogen to prevent contamination by Earth’s atmosphere. A 17.75 mg sample was processed and analyzed for N-heterocycles—organic molecules with a ring structure containing carbon and nitrogen—using high-resolution mass spectrometry at Kyushu University.
The analysis was carried out by a research team, whose members are part of the OSIRIS-REx sample analysis team, consisting of Associate Professor Yasuhiro Oba of Hokkaido University, Principal Researcher Yoshinori Takano of JAMSTEC and Keio University, Dr. Toshiki Koga of JAMSTEC, Professor Hiroshi Naraoka of Kyushu University, and Associate Professor Yoshihiro Furukawa of Tohoku University.
The analysis revealed that the concentration of N-heterocycles is approximately 5 nmol/g, 5–10 times higher than that reported from Ryugu. In addition to the five nitrogenous bases—adenine, guanine, cytosine, thymine and uracil—required for building DNA and RNA, the researchers also found xanthine, hypoxanthine, and nicotinic acid (vitamin B3).
“In previous research, uracil and nicotinic acid were detected in the samples from asteroid Ryugu, but the other four nucleobases were absent. The difference in abundance and complexity of N-heterocycles between Bennu and Ryugu could reflect the differences in the environment to which these asteroids have been exposed in space,” Koga explains.
Samples from the meteorites Murchison and Orgueil were also processed and analyzed previously under identical conditions for comparison. The research team observed that the ratio of purines (adenine and guanine) to pyrimidines (cytosine, thymine and uracil) was much lower in the Bennu samples compared to both Murchison and Orgueil.
“There are multiple possible reasons for this observed difference,” Oba says. “They may be due to differences in parent bodies or formation pathways, or the Bennu asteroid was exposed to a cold molecular cloud environment where pyrimidine formation is more likely to occur.”
“Our findings, which contribute to the larger picture painted by all the authors of the paper, indicate that nucleobase chemistry in the Bennu samples must be further studied,” concluded Naraoka. Another important result of this study is that, by comparing meteorites with Bennu samples, a reference for the reanalysis of other meteorites in collections across the globe has been created.
Bennu sample OREX-800044-101
OREX-800044-101, the sample that was analysed by the Japanese members of the OSIRIS-REx sample analysis team. (Photo provided by Yasuhiro Oba)
Scanning electron microscope images of trona found in samples of the asteroid Bennu returned by NASA’s OSIRIS-REx mission.
Trona is water-bearing sodium carbonate, also known commonly as soda ash.
Each needle is less than a micrometer wide by 5–10 micrometers in length; a human hair is about 100 micrometers wide. The needles form a vein that cuts through the clay-rich rock around it, with small pieces of rock also resting on top of the sodium carbonate needles.
These minerals formed on Bennu’s parent body through the evaporation of salty, sodium-rich waters more than 4.5 billion years ago during the birth of the solar system. As this water evaporated, it formed minerals rich in sodium, carbon, sulfur, phosphorus, chlorine and fluorine.
These minerals formed much like they do today in soda lakes on Earth and subsurface oceans on icy moons and dwarf planets of the outer solar system, including Saturn’s moon Enceladus and the dwarf planet Ceres.
Credit: Rob Wardell, Tim Gooding and Tim McCoy, Smithsonian.
A new analysis of samples from the asteroid Bennu, NASA’s first asteroid sample captured in space and delivered to Earth, reveals that evaporated water left a briny broth where salts and minerals allowed the elemental ingredients of life to intermingle and create more complex structures. The discovery suggests that extraterrestrial brines provided a crucial setting for the development of organic compounds.
In a paper published today, Jan. 29, in the journal Nature, scientists at the Smithsonian’s National Museum of Natural History describe a sequence of evaporated minerals that date back to the early formation of the solar system. The assortment of minerals includes compounds that have never been observed in other extraterrestrial samples.
“We now know from Bennu that the raw ingredients of life were combining in really interesting and complex ways on Bennu’s parent body,” said Tim McCoy, the museum’s curator of meteorites and the co-lead author on the new paper. “We have discovered that next step on a pathway to life.”
Bennu’s parent asteroid, which formed around 4.5 billion years ago, seems to have been home to pockets of liquid water. The new findings indicate that water evaporated and left behind brines that resemble the salty crusts of dry lakebeds on Earth.
A Historic Mission
Bennu has long intrigued researchers due to its near-Earth orbit and carbon-rich composition. Scientists posited that the asteroid contained traces of water and organic molecules and theorized that similar asteroids could have brought these materials to a primordial Earth.
In 2020, NASA’s OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification and Security-Regolith Explorer) spacecraft collected samples from Bennu, becoming the first U.S. space mission to collect a sample from the surface of an asteroid and the only sample collected from a planetary body in nearly 50 years—since the Apollo missions. In September 2023, as OSIRIS-REx soared past Earth, it dropped a capsule containing the Bennu samples. When the capsule touched down in the Utah desert, scientists were on site to retrieve it and protect the samples inside from terrestrial contamination.
In total, OSIRIS-REx collected around120 grams of material, which is about the weight of a bar of soap and double the mission-required amount. The invaluable samples were divvied up and loaned to researchers around the world to analyze. This included Sara Russell, a cosmic mineralogist at the Natural History Museum in London and the co-lead author on the new paper with McCoy.
“It’s been an absolute joy to be involved in this amazing mission, and to collaborate with scientists from around the world to attempt to answer one of the biggest questions asked by humanity: how did life begin,” Russell said. “Together we have made huge progress in understanding how asteroids like Bennu evolved, and how they may have helped make the Earth habitable.”
A Surprising Discovery
NASA loaned the Smithsonian multiple Bennu samples (one of which is on display). McCoy and his colleagues analyzed these specimens using the museum’s state-of-the-art scanning electron microscope, funded in part through the Smithsonian Gem and Mineral Collectors donor group. This allowed the researchers to inspect microscopic features on asteroid fragments less than a micrometer—or 1/100th the width of a human hair—in size.
The team was surprised to find traces of water-bearing sodium carbonate compounds in the Bennu samples studied at the museum. Commonly known as soda ash or by the mineral name trona, these compounds have never been directly observed in any other asteroid or meteorite. On Earth, sodium carbonates often resemble baking soda and naturally occur in evaporated lakes that were rich in sodium, such as Searles Lake in the Mojave Desert.
The surprising discovery of sodium carbonate prompted McCoy to examine mineral specimens in the museum’s National Mineral Collection that contained the compound. He also reached out to his teammates around the world to see if they had observed anything noteworthy in other Bennu samples. The scientists discovered 11 minerals in total that likely existed in a brine-like environment on Bennu’s parent body.
Bennu’s brine differs from terrestrial brines due to its mineral makeup. For example, the Bennu samples are rich in phosphorus, which is abundant in meteorites and relatively scarce on Earth. The samples also largely lack boron, which is a common element in hypersaline soda lakes on Earth but extremely rare in meteorites.
The researchers posit that similar brines likely still exist on other extraterrestrial bodies, including the dwarf planet Ceres and Saturn’s icy moon Enceladus where spacecraft have detected sodium carbonate. These brines likely also exist on other asteroids, and McCoy and his colleagues plan to reexamine meteorite specimens in the museum’s collection. While some of the salts observed in the Bennu brine would break down in Earth’s atmosphere, these minerals may leave telltale traces on meteorites that past scientists may have missed.
A Pathway Toward Life
While the Bennu brines contain an intriguing suite of minerals and elements, it remains unclear if the local environment was suitable to craft these ingredients into highly complex organic structures.
“We now know we have the basic building blocks to move along this pathway towards life, but we don’t know how far along that pathway this environment could allow things to progress,” McCoy said.
A second study, publishing concurrently in the journal Nature AstronomyJan. 29, offers additional insights into Bennu’s composition. This paper describes multiple protein-building amino acids in the Bennu samples. It also reports the discovery of the five nucleobases that make up RNA and DNA. Some of these compounds have not been observed in meteorites that fall to Earth. Senior scientists Danny Glavin and Jason Dworkin at NASA Goddard Space Flight Center in Greenbelt, Maryland, are lead authors on the Nature Astronomy paper.
The two new studies are among the first published analyses of the Bennu samples. The Nature paper co-led by McCoy and Russell is also a major milestone in the National Museum of Natural History’s initiative, Our Unique Planet. As a public–private research partnership, Our Unique Planet investigates what sets Earth apart from its cosmic neighbors by exploring the origins of the planet’s oceans and continents as well as how minerals may have served as templates for life.
McCoy thinks the new discoveries illustrate the scientific legacy of the OSIRIS-REx mission as the samples it collected will fuel research for decades. The samples also highlight how much is left to learn about Bennu.
“This is the kind of finding you hope you’re going to make on a mission,” McCoy said. “We found something we didn’t expect, and that’s the best reward for any kind of exploration.”
In addition to McCoy, Smithsonian-affiliated co-authors included Cari Corrigan, Rob Wardell, Tim Gooding and Tim Rose. This study also included authors affiliated with the University of Arizona; NASA; Goethe University; Curtin University; Côte d'Azur University; the University of California, Berkeley; California State University; Purdue University; the University of Manchester; Hokkaido University; the University of Rochester; Lawrence Berkeley National Laboratory; University of Queensland; Jean Monnet University; the Southwest Research Institute; Open University; the Royal Ontario Museum; the University of Tokyo; Rowan University; and the American Museum of Natural History.
This research was supported by NASA as well as UK Research and Innovation, the UK Science and Technology Facilities Council and the Canadian Space Agency.
NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provided overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator. The university leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Littleton, Colorado, built the spacecraft and provided flight operations.
About the National Museum of Natural History
The National Museum of Natural History is connecting people everywhere with Earth’s unfolding story. It is one of the most visited natural history museums in the world. Opened in 1910, the museum is dedicated to maintaining and preserving the world’s most extensive collection of natural history specimens and human artifacts. The museum is open daily, except Dec. 25, from 10 a.m. to 5:30 p.m. Admission is free. For more information, visit the museum on its website and blog and on Facebook, Twitter and Instagram.
Earth-originating examples of minerals found in Bennu samples. These specimens are from the U.S. National Mineral Collection at the Smithsonian’s National Museum of Natural History and show the minerals observed in Bennu samples as formed and found on Earth. Four of these minerals had not been previously observed in extraterrestrial samples: gaylussite, villiaumite, thenardite, trona.
Foreground, left to right: calcite, gaylussite, sylvite with halite, villiaumite.
Calcite from Saint Joe Lead District, Missouri, U.S. (NMNH 134335). Calcite (calcium carbonate) is the first mineral to form from evaporation on Bennu.
Gaylussite (white coating) from Searles Lake, California, U.S. (NMNH 102881) on trona. Gaylussite (water-bearing sodium calcium carbonate) is typically the first sodium-bearing mineral to form from evaporating brines on Earth and likely formed the same way on Bennu.
Sylvite with associated halite from Stassfurt, Germany (NMNH 56103). Sylvite (potassium chloride) and halite (sodium chloride; common table salt) form late in salty, evaporating fluids. As in this sample, these two minerals are found in association in Bennu.
Villiaumite from Murmanskaja, Russia (NMNH 176297). Villiaumite (sodium fluoride) is the last phase formed during evaporation of the salty, sodium-rich water on Bennu.
Background, left to right: magnetite, thenardite, trona.
Magnetite from St. Lawrence County, New York, U.S. (NMNH R 20522, from the Roebling Collection). Magnetite (iron oxide) is formed by the precipitation of iron dissolved in fluid early in the evaporation sequence. The distinctive cubic form is observed in samples of Bennu, although at a scale of micrometers.
Thenardite from Deep Springs Valley, California, U.S. (NMNH 94538). Thenardite (sodium sulfate) first appears when the brine becomes sodium-rich, lending the moniker “soda lakes” to bodies of water on Earth. On Bennu, thenardite is the first sodium-rich mineral to form and the first occurrence of oxidized sulfur.
Trona from Searles Lake, California, U.S. (NMNH 166722). Trona (water-bearing sodium carbonate) forms in the middle of the evaporation sequence, often forming long, thin needles. Trona forms similar needles in the Bennu samples, although thousands of times smaller.
An evaporite sequence from ancient brine recorded in Bennu samples
Article Publication Date
29-Jan-2025
The Moon is not as “geologically dead” as previously thought, new study reveals
A UMD geologist helped develop advanced dating methods to track geological changes on the far side of the moon and found evidence of relatively recent activity.
Credit: Smithsonian Institution, University of Maryland
Scientists have studied the moon’s surface for decades to help piece together its complex geological and evolutionary history. Evidence from the lunar maria (dark, flat areas on the moon filled with solidified lava) suggested that the moon experienced significant compression in its distant past. Researchers suspected that large, arching ridges on the moon’s near side were formed by contractions that occurred billions of years ago—concluding that the moon’s maria has remained dormant ever since.
However, a new study reveals that what lies beneath the lunar surface may be more dynamic than previously believed. Two Smithsonian Institution scientists and a University of Maryland geologist discovered that small ridges located on the moon’s far side were notably younger than previously studied ridges on the near side. Their findings were published in The Planetary Science Journal on January 21, 2025.
“Many scientists believe that most of the moon’s geological movements happened two and a half, maybe three billion years ago,” said Jaclyn Clark, an assistant research scientist in UMD’s Department of Geology. “But we're seeing that these tectonic landforms have been recently active in the last billion years and may still be active today. These small mare ridges seem to have formed within the last 200 million years or so, which is relatively recent considering the moon’s timescale.”
Using advanced mapping and modeling techniques, the team found 266 previously unknown small ridges on the moon’s far side. The ridges typically appeared in groups of 10 to 40 in volcanic regions that likely formed 3.2 to 3.6 billion years ago in narrow areas where there may be underlying weaknesses in the moon’s surface, according to the researchers. To estimate the age of these small ridges, the researchers used a technique called crater counting. They found that the ridges were notably younger than other features in their surroundings.
“Essentially, the more craters a surface has, the older it is; the surface has more time to accumulate more craters,” Clark explained. “After counting the craters around these small ridges and seeing that some of the ridges cut through existing impact craters, we believe these landforms were tectonically active in the last 160 million years.”
Interestingly, Clark noted that the far-side ridges were similar in structure to ones found on the moon’s near side, which suggests that both were created by the same forces, likely a combination of the moon’s gradual shrinking and shifts in the lunar orbit. The Apollo missions detected shallow moonquakes decades ago; the new findings suggest that these small ridges might be related to similar seismic activity. Learning more about the evolution of the lunar surface could have important implications for the logistics of future moon missions.
“We hope that future missions to the moon will include tools like ground penetrating radar so researchers can better understand the structures beneath the lunar surface,” Clark said. “Knowing that the moon is still geologically dynamic has very real implications for where we’re planning to put our astronauts, equipment and infrastructure on the moon.”
Recent Tectonic Deformation of the Lunar Far Side, Maria and South Pole Aitken Basin
Article Publication Date
28-Jan-2025
UMD astronomer prepares for upcoming NASA mission to investigate mysterious moon domes
With NASA’s selection of a partner to deliver the Lunar VISE mission payload to the moon’s Gruithuisen Domes, scientists take another step toward understanding lunar formation and evolution.
A rendering of Firefly’s Blue Ghost lunar lander and a rover developed for the company’s third mission to the Moon as part of NASA’s CLPS (Commercial Lunar Payload Services) initiative.
NASA recently announced that Firefly Aerospace will deliver the Lunar Vulkan Imaging and Spectroscopy Explorer (Lunar-VISE) payload to the Gruithuisen Domes, one of the most enigmatic locations on the moon. Led by the University of Central Florida (UCF) and supported by partners including the University of Maryland, the Lunar-VISE project aims to investigate the Domes’ inexplicable origins—and whether the moon’s surface contains potential resources for future lunar exploration.
As a co-investigator and instrument scientist of the project, UMD Professor of Astronomy and Geology Jessica Sunshine sees the announcement as a major milestone in the effort to learn more about the moon’s volcanic history and evolution over time.
“We are beginning to have actual hardware and are building our instruments, and now we know how we will get them deployed on the lunar surface and what our rover will look like,” Sunshine said. “What started as a concept and then figures in a proposal is now amazingly really happening. While the project has a lot of work to do, particularly as we integrate with Firefly, this marks a new exciting phase that gets us tantalizingly close to going from paper to the moon.”
The Lunar-VISE mission, currently in its development phase and slated for a 2028 launch date, will travel across the Gruithuisen Domes on the near side of the moon for 10 days. One of Lunar-VISE’s primary goals is to investigate how these silica-rich volcanic domes formed—a process that remains a mystery to scientists because of the moon’s lack of Earth-like conditions (such as oceans and plate tectonics) that can create similar features. The instruments aboard Firefly’s rover will also conduct detailed studies of the lunar surface in the area, studying ancient lava flows surrounding the landing site and other important geologic features that may help scientists reconstruct the moon’s history from formation to its current state.
Sunshine says that for much of the first half of 2025, the Lunar-VISE team will assemble, test and calibrate flight instruments for the upcoming mission—including visible and near-infrared cameras used to detect electromagnetic waves for remote sensing and imaging. The team hopes to complete the final testing of components by August 2025 to ensure they meet all operational requirements and safety standards for lunar deployment by the project’s official launch date.
“I’m very proud of our Lunar-VISE team in developing, building and testing our payload instruments and getting us ready for integration onto Firefly’s [Blue Ghost 3] lunar lander and rover,” said the project’s principal investigator Kerri Donaldson Hanna, an associate professor in UCF’s Department of Physics. “The Lunar-VISE team is excited to work with Firefly to plan our science and exploration operations at the Gruithuisen Domes in 2028.”
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This article was adapted from text provided by the University of Central Florida.
Follow the water: Searching for a lunar oasis
New research may help astronauts locate viable water sources on the moon
As humankind imagines living off-planet — on the moon, Mars and beyond — the question of how to sustain life revolves around the physical necessities of oxygen, food and water. We know there is water on the moon, but how do we find it? Is it in the craters? The shadowed regions? The poles? Knowing where to look gives astronauts the best chance at successfully living on the moon, something that has, heretofore, remained the stuff of science fiction.
Researchers from the University of California San Diego may help bring science fiction to reality by providing a divining rod to guide future space missions, including NASA’s Artemis campaign, which seeks to explore and, eventually, inhabit the moon. Their work appears in a special issue of Proceedings of the National Academy of Sciences(PNAS)called “Water on the Moon and Mars,” which features Artemis I on its cover.
The researchers included the father-son team of Mark Thiemens, UC San Diego Distinguished Professor of Chemistry and Biochemistry, and Maxwell Thiemens, a research fellow at the Vrije Universiteit Brussel, who is also an alumnus of Scripps Institution of Oceanography.
In 1967, Nobel laureate Harold Urey and James Arnold — both faculty members in UC San Diego’s Department of Chemistry — were among the first to receive Apollo 11 lunar samples. Urey was one of the first scientists to theorize that there was water on the moon, particularly in the permanently shadowed regions of the moon’s poles. Today, scientists believe that water on the moon originated from one of three sources:
indigenous to the moon,
created by solar winds (where hydrogen from the sun reacts with oxygen at high energy on the moon and likely Mars to create water)
deposition (from icy comets that have crashed onto the lunar surface).
On Earth, human civilizations often bubble up near bodies of water and it would be no different in space. On the moon, it’s important to know the origin of the water sources because it will give astronauts guidance on where it would be most prudent to set up bases and habitats.
To learn about the origin of water on the moon, Morgan Nunn Martinez (who was a UC San Diego graduate student at the time) extracted very small amounts from lunar rocks collected from the 1969 Apollo 9 mission. It may sound implausible to get water from a rock, but it is possible through “thermal release,” a process where lunar samples were heated to 50, 150 and 1,000 degrees Celsius (122, 302, and 1,832 degrees Fahrenheit respectively). As it turns out, these rocks were surprisingly “wet.”
The lowest temperatures released lightly bound water molecules — those molecules that are attached to other molecules (in this case, lunar rock) through a weak attraction. At 1,000 degrees Celsius, tightly bound water molecules, which are more deeply embedded in the rock, were released.
Through this process, gas water molecules are collected, then purified so that only the oxygen remains. The team then measured the composition of three different oxygen isotopes.
Isotopes are atoms of the same element that have varying numbers of neutrons, which changes their mass — the more neutrons, the heavier the atom. These measurements are particularly useful in determining a substance’s origin and age.
Think of it like space forensics. In the way humans have unique fingerprints, astronomical objects, like comets and the sun, have unique signatures. Scientists are able to look at the oxygen isotope measurements and determine the origin of the water.
Their data revealed that most of the lunar water likely originated from the moon itself or from comet impacts. Contrary to popular belief, solar winds did not significantly contribute to the moon’s water stores.
“What’s nice about this research is that we’re using the most advanced scientific measurements and it supports common sense ideas about lunar water — much of it has been there since the beginning and more was added by these icy comet impacts,” stated Maxwell Thiemens. “The more complicated method of solar wind-derived water doesn’t appear to have been that productive.”
Although not a main thrust of the paper, the researchers also measured samples from Mars. If NASA’s Artemis program is able to successfully colonize humans on the moon, it would bode well for the ultimate mission of inhabiting Mars.
“This kind of work hasn’t been done before and we think it can provide NASA with some valuable clues about where water is located on the moon,” stated Mark Thiemens. “The real goal of Artemis is to get to Mars. Our research shows that likely there is at least as much water on Mars as on the moon, if not more.”
Of course, locating the water is only the first step. Being able to extract it from lunar rocks and soil in quantities large enough to sustain life will require further technological advancements and discovery.
Full list of authors: Maxwell Thiemens (Vrije Universiteit Brussel), Morgan Nunn Martinez and Mark Thiemens (UC San Diego).
This research was supported, in part, by a NASA Earth and Space Science Fellowship, a Zonta International Amelia Earhart Fellowship and the Achievement Rewards for College Scientists Fellowship.
Triple oxygen isotopes of lunar water unveil indigenous and cometary heritage
PULSAR consortium designs nuclear power system for lunar missions
Wednesday, 29 January 2025
The PULSAR research project, led by Belgian engineering firm Tractebel, has unveiled the conceptual design of a plutonium-238-fuelled radioisotope power system for lunar space missions.
(Image: Tractebel)
The project - announced in June 2022 - is being funded by the European Commission's Euratom Research and Training Programme, and is in addition to the study Tractebel is already carrying out for the European Space Agency on the possibility of producing Pu-238 in the European Union.
The consortium includes the Joint Research Centre of the European Commission, the Belgian Nuclear Research Centre (SCK-CEN), the French Alternative Energies and Atomic Energy Commission (CEA), INCOTEC, ArianeGroup, Airbus Defense and Space, the University of Bourgogne Franche Comté and Arttic.
Tractebel says that with current nuclear batteries, radioisotope thermoelectric generators (RTGs), "substantial amounts of fuel and large RTG are needed to power missions, which increases the weight to be launched by the space rocket … the project aims to significantly increase the efficiency of the radioisotope power system thanks to an advanced Stirling engine".
PULSAR also aims to develop technology and capabilities in Europe to produce Pu-238 - currently no Pu-238 or radioisotope power system are manufactured in Europe and "as space has become a strategic and economic priority for Europe" its dependence on other countries "is a major concern".
Completed at the end of 2024, the project delivered significant outcomes, including: a conceptual radioisotope power system design tailored for lunar applications; a feasibility study for Pu-238 production in Europe; and a market analysis exploring the potential of dynamic power systems beyond space applications.
The PULSAR consortium's radioisotope power system (RPS) is designed to support a lunar rover or cargo carrier requiring 100–500 We. It incorporates safety measures for launch from the Guiana Space Centre and features two Stirling engines powered by a centrally located Pu-238 heat source. The modular design ensures resilience against motor failure, with an expected thermo-electrical conversion efficiency of 20%.
Tractebel said its nuclear experts conducted comprehensive engineering studies, including structural integrity checks, radiation dose assessments, thermal analysis, and mechanical assembly development. The team developed a 3D mechanical and thermal model to simulate lunar conditions, providing a foundation for future design iterations and higher Technical Readiness Levels. It said this work lays the groundwork for Europe's participation in the upcoming Argonaut lunar lander mission.
"What the PULSAR consortium has achieved will help position Europe as an autonomous global leader in space nuclear technologies," said Tractebel's Brieuc Spindler, PULSAR project manager. "Tractebel leads European research projects focused on advancing nuclear technologies for space exploration, including RPS and radioisotope production, electric propulsion, and fission surface systems. By leveraging our nuclear expertise, we are pushing the boundaries of space exploration and enabling Europe to lead in this final frontier."
The space community has relied mainly on photovoltaic power systems, a technology that was originally developed for the purpose of space applications and has found many terrestrial uses. However, these systems pose severe limitations for missions to places like the outer solar system. The available solar energy reduces with the square of the distance from the sun. For example, at Saturn the solar power density is a hundred times lower than at Earth. There is also the issue of the two week-long nights on the Moon.
It has meant that radioisotope power sources - sometimes referred to as nuclear batteries - fuelled with Pu-238 have generally been used in space missions since the early 1960s. Radioisotope thermoelectric generators and radioisotope heater units can provide power and heat continuously over long, deep space missions. Pu-238 is made by irradiating neptunium-237, recovered from research reactor fuel or special targets, in research reactors.
2024 ISS National Lab Annual Report highlights momentum in space-based R&D
More than 100 payloads delivered and more than 50 papers published as international space station national laboratory accelerates discovery in low earth orbit
International Space Station U.S. National Laboratory
KENNEDY SPACE CENTER (FL), January 28, 2025 – The International Space Station (ISS) National Laboratory highlighted the rapid growth of space-based R&D in its annual report, released today by the Center for the Advancement of Science in Space® (CASIS®). Over the past fiscal year, the ISS National Lab sponsored more than 100 payloads delivered to the orbiting laboratory—the second-highest annual total to date. Also this year, ISS National Lab-related results were published in 51 peer-reviewed articles—the most ever in a year—underscoring the vital role of the ISS National Lab in advancing scientific discovery and innovation.
Since 2011, CASIS has managed the ISS National Lab under a Cooperative Agreement with NASA, enabling access to the space station to benefit humanity and stimulate a thriving low Earth orbit (LEO) economy. This partnership with NASA supports the ISS National Lab’s mission to advance space-based R&D, foster a sustainable market economy in space, and pave the way for future commercial LEO destinations (CLDs). The ISS National Lab’s annual report for fiscal year 2024 (October 1, 2023-September 30, 2024) showcases the progress toward these goals.
Below are a few notable accomplishments from FY24:
Of the 103 ISS National Lab-sponsored payloads launched to the space station, 80 percent were from commercial entities, indicating a continued strong interest from private industry to conduct R&D in space.
Nearly 75 percent of newly selected projects in FY24 were from new-to-space users, highlighting the success of ISS National Lab solicitations in attracting new research communities. Of the 31 selected projects, more than half were through ISS National Lab Research Announcements (NLRAs) in the strategic focus areas of technology development, in-space production applications (tissue engineering and biomanufacturing), and workforce development.
More than 50 peer-reviewed articles related to ISS National Lab research—the most identified in a single fiscal year—were published in FY24, bringing the all-time total to nearly 450. Two-thirds of these papers were related to projects funded by the U.S. National Science Foundation (NSF) and the National Institutes of Health (NIH).
An NIH-funded project resulted in a patent filed for a muscle tissue chip system, and an ISS National Lab-sponsored educational project led to a new product: a space station model kit for educators and students.
Nearly $25 million in external, non-NASA funding was committed in support of ISS National Lab-sponsored projects, with almost half from academic and nonprofit institutions—underscoring the value they find in space-based R&D.
The ISS National Lab allocated significant funding to the inaugural Igniting Innovation solicitation, in partnership with NASA’s Biological and Physical Sciences Division. The solicitation offered $7 million to five selected multiflight projects to advance critical cancer research. Most were from academic and nonprofit institutions that matched funding 1:1.
Despite challenging market conditions, startups secured nearly $147 million in funding after the flight of ISS National Lab-sponsored projects, bringing the cumulative total to $2.2 billion.
Subscribership nearly doubled for Upward, official magazine of ISS National Lab, while the Space Station Spotlight newsletter, which launched in FY23, added 1,100 new subscribers in FY24. Both boosted awareness of ISS National Lab activities and R&D results, while a redesigned website doubled page views by creating clearer engagement pathways.
This year, the ISS National Lab prioritized workforce development and STEM career readiness, launching activities to equip students with essential skills. A new corporate donor pledged funding to support these education initiatives over the next three years.
“I am incredibly proud of what we achieved this year,” said Ramon Lugo, principal investigator and chief executive officer of CASIS. “As we continue to work hand in hand with NASA, ourstrong partnership has allowed us to push the limits of what we can accomplish.”
The FY24 Annual Report is now available online. To read about additional ISS National Lab-sponsored research that has launched to the space station, visit our website.
The fact that the cold, dry Mars of today had flowing rivers and lakes several billion years ago has puzzled scientists for decades. Now, Harvard researchers think they have a good explanation for a warmer, wetter ancient Mars.
Building on prior theories describing the Mars of yore as a hot again, cold again place, a team led by researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have determined the chemical mechanisms by which ancient Mars was able to sustain enough warmth in its early days to host water, and possibly life.
“It’s been such a puzzle that there was liquid water on Mars, because Mars is further from the sun, and also, the sun was fainter early on,” said Danica Adams, NASA Sagan Postdoctoral Fellow and lead author of the new paper in Nature Geoscience.
Hydrogen was previously theorized as the magic ingredient, mixed with carbon dioxide in the Martian atmosphere to trigger episodes of greenhouse warming. But the lifetime of atmospheric hydrogen is short, so a more detailed analysis was required.
Now, Adams; Robin Wordsworth, the Gordon McKay Professor of Environmental Science and Engineering at SEAS; and team have performed photochemical modeling – similar to methods used today to track air pollutants – to fill in details of the early Martian atmosphere’s relationship to hydrogen, and how that relationship changed over time.
“Early Mars is a lost world, but it can be reconstructed in great detail if we ask the right questions,” Wordsworth said. “This study synthesizes atmospheric chemistry and climate for the first time, to make some striking new predictions – which are testable once we bring Mars rocks back to Earth.”
Adams modified a model called KINETICS to simulate how a combination of hydrogen and other gases reacting with both the ground and the air controlled the early Martian climate.
She found that during Mars’ Noachian and Hesperian periods, between 4 and 3 billion years ago, Mars experienced episodic warm spells over about 40 million years, with each event lasting 100,000 or more years. These estimates are consistent with geologic features on Mars today. The warm, wet periods were driven by crustal hydration, or water being lost to the ground, which supplied enough hydrogen to build up in the atmosphere over millions of years.
During the fluctuations between warm and cold climates, the chemistry of Mars’ atmosphere was also fluctuating. CO2 is constantly hit by sunlight and converted to CO. In warm periods, the CO could recycle back into CO2, making CO2 and hydrogen dominant. But if it was cold for long enough, the recycling would slow down, build up CO, and bring about a more reduced state, a.k.a. less oxygen. The redox states of the atmosphere thus changed dramatically over time.
“We’ve identified time scales for all of these alternations,” Adams said. “And we’ve described all the pieces in the same photochemical model.”
The modeling work lends potential new insight into conditions that supported prebiotic chemistry – the underpinnings of later life as we know it – during warm periods, and challenges for the persistence of that life during intervals of cold and oxidation. Adams and others are starting to work on finding evidence of those alternations using isotope chemical modeling, and they plan to compare those results to rocks from the upcoming Mars Sample Return mission.
Because Mars lacks plate tectonics, unlike Earth, the surface seen today is similar to that of long ago, making its history of lakes and rivers that much more intriguing. “It makes a really great case study for how planets can evolve over time,” Adams said.
Adams started the work as a Ph.D. student at California Institute of Technology, which hosts the photochemical model she used. The study was supported by NASA and Jet Propulsion Laboratory.
Because Mars lacks plate tectonics, unlike Earth, the surface seen today is similar to that of long ago, making its history of lakes and rivers that much more intriguing. “It makes a really great case study for how planets can evolve over time,” Adams said. Adams started the work as a Ph.D. student at California Institute of Technology, which hosts the photochemical model she used. The study was supported by NASA and Jet Propulsion Laboratory.
Article Publication Date
25-Jan-2025
A super-Earth laboratory for searching life elsewhere in the Universe
An international team, including the UNIGE, has discovered a super-Earth that will enable astronomers to test new hypotheses in the search for life in the Universe.
Thirty years after the discovery of the first exoplanet, we detected more than 7000 of them in our Galaxy. But there are still billions more to be discovered! At the same time, exoplanetologists have begun to take an interest in their characteristics, with the aim of finding life elsewhere in the Universe. This is the background to the discovery of super-Earth HD 20794 d by an international team including the University of Geneva (UNIGE) and the NCCR PlanetS. The new planet lies in an eccentric orbit, so that it oscillates in and out of its star’s habitable zone. This discovery is the fruit of 20 years of observations using the best telescopes in the world. The results are published today in the journal Astronomy & Astrophysics.
‘‘Are we alone in the Universe?’’ For thousands of years, this question was confined to philosophy, and it is only very recently that modern science has begun to provide solid hypotheses and evidence to answer it. However, astronomers are making slow progress. Each new discovery, whether theoretical or observational, adds to the edifice by pushing back the limits of knowledge. This was the case with the discovery in 1995 of the first planet orbiting a star other than the Sun, which earned two UNIGE researchers, Michel Mayor and Didier Queloz, the 2019 Physics Nobel Prize.
Nearly thirty years later, astronomers have taken many small steps towards detecting more than 7,000 of these exoplanets. The current scientific consensus points to the existence of a planetary system for every star in our galaxy. Astronomers are now looking for exoplanets that are easier to characterise or have interesting features to test their hypotheses and consolidate their knowledge. This is the case of planet HD 20794 d, which has just been detected by a team that includes members of the UNIGE Astronomy Department.
In the habitable zone of its star
This promising planet is a super-Earth, a telluric planet larger than the Earth. It is part of a planetary system containing two other planets. It orbits a G-type star, like the Sun, at a distance of just 19.7 light-years, which is, on the scale of the Universe, in the very close neighbourhood of the Earth. This ‘‘closeness’’ makes it easier to study, as its light signals are more visible and stronger. ‘‘HD 20794, around which HD 20794 d orbits, is not an ordinary star,’’ explains Xavier Dumusque, Senior Lecturer and researcher in the Department of Astronomy at the UNIGE and co-author of the study. ‘‘Its luminosity and proximity makes it an ideal candidate for future telescopes whose mission will be to observe the atmospheres of exoplanets directly.’’
The interest in planet HD 20794 d lies in its position in the habitable zone of its star, the zone that delimits the place where liquid water can exist, one of the conditions necessary for the development of life as we know it. This zone depends on several factors, mainly the stellar properties. For stars such as the Sun or HD 20794, it can extend from 0.7 to 1.5 astronomical units (AU), encompassing not only the orbit of the Earth but also that of Mars in the case of the Sun. The exoplanet HD 20794 d takes 647 days to orbit its star, around forty days less than Mars.
Instead of following a relatively circular orbit, like the Earth or Mars, HD 20794 d follows an elliptical trajectory with large changes in the distance to its star during its revolution. The planet thus oscillates between the inner edge of its star HZ (0.75 AU) and outside of it (2 AU) along its orbit. This configuration is of particular interest to astronomers because it allows them to adjust theoretical models and test their understanding of the notion of a planet’s habitability. If there is water on HD 20794 d, it would pass from the state of ice to the liquid state, conducive to the appearance of life, during the planet’s revolution around the star.
Many years of observations
Detecting this super-Earth was not easy and the process was iterative. The team analysed more than twenty years of data from state-of-the-art instruments such as ESPRESSO and HARPS. For the latter, the scientists were able to rely on YARARA, a data reduction algorithm recently developed at the UNIGE. For years, planetary signals had been obscured by noise, making it difficult to discern whether planets actually existed. ‘‘We analysed the data for years, carefully eliminating sources of contamination,’’ explains Michael Cretignier, a post-doctoral researcher at Oxford University, co-author of the study and developer of YARARA during his PhD at UNIGE.
The discovery of HD 20794 d provides scientists with an interesting laboratory for modelling and testing new hypotheses in their search for life in the Universe. The proximity of this planetary system to its bright star also makes it a prime target for next-generation instruments such as the ANDES spectrograph for ESO’s Extremely Large Telescope (ELT). Knowing whether this planet harbours life will still require a number of scientific milestones and a transdisciplinary approach. The conditions for its habitability are already being studied by the new Centre for Life in the Universe (CVU) at the UNIGE’s Faculty of Science.
Revisiting the multi-planetary system of the nearby star HD 20794. Confirmation of a low-mass planet in the habitable zone of a nearby G-dwarf
Article Publication Date
28-Jan-2025
A less ‘clumpy,’ more complex universe?
Researchers combined cosmological data from two major surveys of the universe’s evolutionary history and found that it may have become ‘messier and complicated’ than expected in recent years.
Across cosmic history, powerful forces have acted on matter, reshaping the universe into an increasingly complex web of structures.
Now, new research led by Joshua Kim and Mathew Madhavacheril at the University of Pennsylvania and their collaborators at Lawrence Berkeley National Laboratory suggests our universe has become “messier and more complicated” over the roughly 13.8 billion years it’s been around, or rather, the distribution of matter over the years is less “clumpy” than expected.
“Our work cross-correlated two types of datasets from complementary, but very distinct, surveys,” says Madhavacheril, “and what we found was that for the most part, the story of structure formation is remarkably consistent with the predictions from Einstein’s gravity. We did see a hint for a small discrepancy in the amount of expected clumpiness in recent epochs, around four billion years ago, which could be interesting to pursue.”
The data, published in the Journal of Cosmology and Astroparticle Physics and the preprint server arXiv, comes from the Atacama Cosmology Telescope’s (ACT) final data release (DR6) and the Dark Energy Spectroscopic Instrument’s (DESI) Year 1. Madhavacheril says that pairing this data allowed the team to layer cosmic time in a way that resembles stacking transparencies of ancient cosmic photographs over recent ones, giving a multidimensional perspective of the cosmos.
“ACT, covering approximately 23% of the sky, paints a picture of the universe’s infancy by using a distant, faint light that’s been travelling since the Big Bang,” says first author of the paper Joshua Kim, a graduate researcher in the Madhavacheril Group. “Formally, this light is called the Cosmic Microwave Background (CMB), but we sometimes just call it the universe’s baby picture because it’s a snapshot of when it was around 380,000 years old.”
The path of this ancient light throughout evolutionary time, or as the universe has aged, has not been a straight one, Kim explains. Gravitational forces from large, dense, heavy structures like galaxy clusters in the cosmos have been warping the CMB, sort of like how an image is distorted as it travels through a pair of spectacles. This “gravitational lensing effect,” which was first predicted by Einstein more than 100 years ago, is how cosmologists make inferences about its properties like matter distribution and age.
DESI’s data, on the other hand, provides a more recent record of the cosmos. Based in the Kitt Peak National Observatory in Arizona and operated by the Lawrence Berkeley National Laboratory, DESI is mapping the universe’s three-dimensional structure by studying the distribution of millions of galaxies, particularly luminous red galaxies (LRGs). These galaxies act as cosmic landmarks, making it possible for scientists to trace how matter has spread out over billions of years.
“The LRGs from DESI are like a more recent picture of the universe, showing us how galaxies are distributed at varying distances,” Kim says, likening the data to the universe’s high school yearbook photo. “It’s a powerful way to see how structures have evolved from the CMB map to where galaxies stand today.
By combining the lensing maps from ACT’s CMB data with DESI’s LRGs, the team created an unprecedented overlap between ancient and recent cosmic history, enabling them to compare early- and late-universe measurements directly. “This process is like a cosmic CT scan,” says Madhavacheril, “where we can look through different slices of cosmic history and track how matter clumped together at different epochs. It gives us a direct look into how the gravitational influence of matter changed over billions of years.”
In doing so they noticed a small discrepancy: the clumpiness, or density fluctuations, expected at later epochs didn’t quite match predictions. Sigma 8 (σ8), a metric that measures the amplitude of matter density fluctuations, is a key factor, Kim says, and lower values of σ8 indicate less clumping than expected, which could mean that cosmic structures haven’t evolved according to the predictions from early-universe models and suggest that the universe’s structural growth may have slowed in ways current models don’t fully explain.
This slight disagreement with expectations, he explains, “isn’t strong enough to suggest new physics conclusively—it’s still possible that this deviation is purely by chance.”
If indeed the deviation is not by chance, some unaccounted-for physics could be at play, moderating how structures form and evolve over cosmic time. One hypothesis is that dark energy—the mysterious force thought to drive the universe’s accelerating expansion—could be influencing cosmic structure formation more than previously understood.
Moving forward, the team will work with more powerful telescopes, like the upcoming Simons Observatory, which will refine these measurements with higher precision, enabling a clearer view of cosmic structures.
Mathew Madhavacheril is an assistant professor in the Department of Physics and Astronomy in the School of Arts & Sciences at the University of Pennsylvania.
Joshua Kim is a Ph.D. candidate at Penn Arts & Sciences.
The research was supported by Agencia Nacional de Investigación y Desarrollo (Basal project FB210003); Atacama Cosmology Telescope Project (Grants AST-0408698, AST-0965625, AST-1440226); Canada Foundation for Innovation; Cambridge International Trust; Chinese Academy of Sciences; Chinese National Natural Science Foundation; Dark Energy Spectroscopic Instrument Member Institutions; European Research Council (Grant No. 851274 and No. 849169); Fermi Research Alliance, (Contract No. DE-AC02-07CH11359); French Alternative Energies and Atomic Energy Commission; Fundación Mauricio y Carlota Botton; Gordon and Betty Moore Foundation; Heising-Simons Foundation; "la Caixa" Foundation; Lawrence Berkeley National Laboratory (Contract No. DE-AC02-05CH11231); NASA (Grants NNX13AE56G, NNX14AB58G, and 21-ATP21-0145); National Astronomical Observatories of China; National Council of Science and Technology of Mexico; National Energy Research Scientific Computing Center; National Research Foundation of South Africa; National Science Foundation (Grants AST-2307727, AST-2153201, PHY-0355328, PHY-0855887, PHY-1214379, AST-0950945, AST-2108126); Princeton University; Science and Technologies Facilities Council of the United Kingdom; Swiss National Science Foundation (Fellowship No. 186879); and the University of Pennsylvania.
The Atacama Cosmology Telescope DR6 and DESI: structure formation over cosmic time with a measurement of the cross-correlation of CMB lensing and luminous red galaxies
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