Can they unlock the origins of life?

Analysis of a sample from the asteroid Bennu found essential life elements and hints of a watery past, providing insights into the origin of the Solar System and prebiotic chemistry.

• A preliminary analysis of the asteroid Bennu model is back NASAs OSIRIS-REx The mission revealed dust rich in carbon, nitrogen and organic compounds, all of which are essential elements for life as we know it. Dominated by clay minerals, especially serpentine, the sample reflects the type of rock found in Earth’s mid-ocean ridges.
• Magnesium-sodium phosphate found in the sample indicates that the asteroid may have broken off from an ancient, small, primitive ocean world. The phosphate came as a surprise to the team, as the mineral was not detected by the OSIRIS-REx spacecraft while at Bennu.
• A similar phosphate-yielding asteroid was detected in the Ryuku sample JaxaBy the (Japan Aerospace Exploration Agency) Hayabusa2 mission in 2020, the magnesium-sodium phosphate found in the Bennu sample stood out for its purity (i.e., the lack of other materials added to the mineral) and its grain size, which was unprecedented. In any meteorite sample.

This mosaic of Bennu was created using close-up observations of the asteroid by NASA’s OSIRIS-REx spacecraft over two years. Credit: NASA/Goddard/University of Arizona

Findings from the composition of the asteroid Bennu

Scientists are looking forward to sending a 4.3-ounce (121.6-gram) sample of the ancient asteroid Bennu back to Earth, collected by NASA’s OSIRIS-REx (Origination, Spectral Interpretation, Resource Identification and Conservation – Regolith Explorer). Last fall. They believed the material held secrets of the solar system’s past and the prebiotic chemistry that led to life on Earth. A preliminary analysis of the Bennu model, published recently Meteorites & Planetary ScienceThis enthusiasm proves to be needed.

The OSIRIS-REx sample analysis team found that Bennu contains the original material that formed our Solar System. Asteroid dust is rich in carbon and nitrogen and organic compounds, all essential elements for life as we know it. The sample contained magnesium-sodium phosphate, which was a surprise to the research team because it was not seen in remote sensing data collected by the spacecraft at Bennu. Its presence in the sample indicates that the asteroid may have long ago separated from a small, primitive ocean world.

A view of eight sample plates containing the final object of the asteroid Bennu. Dust and rocks were poured into the trays from the tray on top of the head of the touch-and-go sample acquisition mechanism (TAGSAM). 51.2 g was collected from this pour, bringing the final mass of the asteroid sample to 121.6 g. Credit: NASA/Erika Blumenfeld & Joseph Aebersold

Analysis of the Bennu sample revealed intriguing insights into the asteroid’s composition. Dominated by clay minerals, especially serpentine, the pattern reflects the type of rock found at Earth’s mid-ocean ridges, where material from the crust beneath the Earth’s crust meets water.

This interaction not only results in clay formation; It forms various minerals such as carbonates, iron oxides and iron sulphides. But the most unexpected discovery was the presence of water-soluble phosphates. These compounds are the building blocks of biochemistry for all life known on Earth today.

While a similar phosphate was found in a sample of asteroid Ryuku delivered by JAXA’s (Japan Aerospace Exploration Agency’s) Hayabusa2 mission in 2020, the magnesium-sodium phosphate found in the Bennu sample stands out for its purity—that is, the lack of other materials. The mineral – and the size of its grains – is unprecedented in any meteorite sample.

A small portion of a sample of asteroid Bennu returned by NASA’s OSIRIS-REx mission, shown in microscopic images. The top-left panel shows a millimeter-long dark penne particle with an outer shell of bright phosphate. The other three panels show progressively magnified views of particles of particles breaking through a bright vein of phosphate captured by a scanning electron microscope. Credit: Lauretta & Connolly et al. (2024) Meteorites & Planetary Sciencedoi:10.1111/maps.14227

The discovery of magnesium-sodium phosphates in the Bennu sample raises questions about the geochemical processes that accumulated these elements and provides valuable clues about Bennu’s historical conditions.

„The presence and condition of phosphates, along with other elements and compounds in Bennu, suggests a watery past for the asteroid,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona and co-lead author of the paper. Tucson. „Bennu may once have been part of a wet world. However, this hypothesis requires further investigation.”

„Osiris-Rex yielded what we expected: a large, beautiful asteroid sample rich in nitrogen and carbon from a formerly wet world,” said Jason Dworkin, co-author of the paper and Osiris-Rex project scientist at NASA’s Goddard Space. Aviation Center in Greenbelt, Maryland.

NASA’s OSIRIS-REx spacecraft leaves the surface of asteroid Bennu after collecting a sample. Credit: NASA’s Goddard Space Flight Center/CI Laboratory/SVS

Despite its possible history of interaction with water, Bennu is a chemically primitive asteroid, with basic proportions similar to the Sun.

„The sample we returned is now the largest reservoir of unaltered asteroid material on Earth,” Lauretta said.

The combination provides a glimpse into the earliest days of our solar system, 4.5 billion years ago. These rocks have not melted or re-evolved since their inception, retaining their original state and confirming their ancient origin.

The team confirmed that the asteroid is rich in carbon and nitrogen. These elements are important for understanding the environments in which Bennu’s materials originated and the chemical processes that transform simple elements into complex molecules, which lay the foundation for life on Earth.

„These findings underscore the importance of collecting and studying material from asteroids like Bennu — especially the low-density material that typically burns up as it enters Earth’s atmosphere,” Lauretta said. „This material holds the key to unraveling the complex processes of solar system formation and the prebiotic chemistry that may have contributed to life on Earth.”

Dozens of laboratories in the U.S. and around the world will receive parts of the Bennu sample from NASA’s Johnson Space Center in Houston in the coming months, and several scientific papers detailing analyzes of the Bennu sample are expected over the next few years. OSIRIS-REx Model Analysis Group.

„The Bennu samples are really beautiful extraterrestrial rocks,” said Harold Connolly, co-lead author of the paper and OSIRIS-REx mission sample scientist at Rowan University in Glassboro, New Jersey. „Each week, the OSIRIS-REx Model Analysis Team’s analysis provides new and sometimes surprising discoveries that help place important constraints on the origin and evolution of Earth-like planets.”

Launched on September 8, 2016, the OSIRIS-REx spacecraft traveled to the near-Earth asteroid Bennu and collected a sample of rocks and dust from the surface. OSIRIS-REx, the first US mission to collect a sample from an asteroid, delivered the sample to Earth on September 24, 2023.

Note: Asteroid (101955) Bennu in the lab: Characteristics of a sample collected by OSIRIS-REx Dante S. Loretta, Harold C. Connolly, Joseph E. Aebersold, Connell M.O.D. Alexander, Ronald-L. Ballouz, Jessica J. Barnes, Helena C. Bates, Carina A. Bennett, Laurinne Blanche, Erika H. Blumenfeld, Simon J. Clemett, George D. Cody, Daniella N. DellaGiustina, Jason P. Dworkin, Scott A. Eckley, Dionysus i. Fustoukos, Ian A. Franchi, Daniel B. Clavin, Richard C. Greenwood, Pierre Honeycore, Victoria E. Hamilton, Dolores H. Hill, Takahiro Hiroi, Kana Ishimaru, Fred Jordan, Hannah H. Kaplan, Lindsay B. Keller, Ashley J. King, Piers Koefoed, Melissa K. Kontogiannis, Loan Le, Robert J. Macke, Timothy J. McCoy, Ralph E. Milliken, Jens Najorka, Ann N. Nguyen, Maurizio Pajola, Anjani T. Polit, Kevin T. Polit Reiter, Heather L. Roper, Sarah S. Russell, Andrew J. Ryan, Scott A. Sandford, Paul F. Schofield, Cody D. Schultz, Laura B. Seifert, Shoko Tachibana, Kathy L. Thomas-Gebrda, Michelle S. Thompson, Valerie Du, Filippo Dusberti, Kun Wang, Thomas J. Zega, CWV Volner and , 26 June 2024, Meteorites & Planetary Science.
DOI: 10.1111/maps.14227

NASA’s Goddard Space Flight Center in Greenbelt, Maryland provided overall mission management, systems engineering, and safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, was the principal investigator. The university leads the scientific team and the mission’s scientific monitoring planning and data processing. Lockheed Martin Space in Littleton, Colorado, built the spacecraft and provided flight operations. Goddard and KinectX Aerospace are responsible for piloting the OSIRIS-REx spacecraft. Treatment for OSIRIS-REx is taking place at NASA Johnson. International partnerships in this mission include the OSIRIS-REx laser altimeter instrument from CSA (Canadian Space Agency) and asteroid sampling science collaboration with JAXA’s Hayabusa2 mission. OSIRIS-REx is the third mission in NASA’s New Frontiers program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.