Nine months have passed since NASA\u2019s OSIRIS-REx returned its samples of asteroid Bennu to Earth. The samples are some of the Solar System\u2019s primordial, pristine materials. They\u2019ve made their way into scientists\u2019 hands, and their work is uncovering some surprises.<\/p>\n
Some of the material in the samples indicates that Bennu had a watery past. <\/p>\n
<\/p>\n NASA chose Bennu for the OSIRIS-REx sampling mission for several reasons. First, it\u2019s a near-Earth asteroid (NEA), so it\u2019s relatively close to Earth. It\u2019s also not very large at about 500 meters in diameter and rotates slowly enough to allow for a safe sampling procedure. <\/p>\n But the overarching reason was probably its composition. It\u2019s a B-type asteroid, a subtype of carbonaceous asteroids, which means it contains organic molecules. Finding organic molecules throughout the Solar System is one way of tracing its origin and formation.<\/p>\n Returning samples to Earth is the best and most complete way to study asteroids. Asteroid fragments that fall to Earth are scientifically valuable. But much of their lighter material simply burns up when entering Earth\u2019s atmosphere, leaving a huge crater in our understanding. <\/p>\n Space missions always seem to surprise us somehow. If they didn\u2019t, there\u2019d be less impetus to send them. In this case, the sample contains chemicals that OSIRIS-REx didn\u2019t spot when it was studying Bennu. <\/p>\n \u201cBennu potentially could have once been part of a wetter world.\u201d<\/p>\n Dante Lauretta, Principal Investigator, OSIRIS-REx mission<\/cite><\/p><\/blockquote>\n<\/figure>\n New research in the journal Meteoritics and Planetary Science presents these findings. It\u2019s titled \u201cAsteroid (101955) Bennu in the laboratory: Properties of the sample collected by OSIRIS-REx.\u201d The co-lead author is Dante S. Lauretta, the principal investigator for the OSIRIS-REx mission and the Regents Professor of Planetary Sciences at the University of Arizona Lunar and Planetary Laboratory. The paper is an overview of the sample and serves as a catalogue from which researchers can request sample material for their research. <\/p>\n \u201cFinally having the opportunity to delve into the OSIRIS-REx sample from Bennu after all these years is incredibly exciting,\u201d Lauretta said in a press release. \u201cThis breakthrough not only answers longstanding questions about the early solar system but also opens new avenues of inquiry into the formation of Earth as a habitable planet. The insights outlined in our overview paper have sparked further curiosity, driving our eagerness to explore deeper.\u201d<\/p>\n \u201cWe describe the delivery and initial allocation of this asteroid sample and introduce its bulk physical, chemical, and mineralogical properties from early analyses,\u201d the authors write in their paper. The 120-gram sample dates back billions of years. It\u2019s pristine, meaning it hasn\u2019t melted and resolidified since it was formed.<\/p>\n The astromaterials curation team at NASA\u2019s Johnson Space Center used the Advanced Imaging and Visualization of Astromaterials (AIVA) procedure to document the condition of the sample and the sampling equipment. This was done while the sample was still inside its glovebox, which is highly reflective for this purpose. This is a meticulous process involving hundreds of images stacked together. <\/p>\n Overall, the sample is dark. But there are brighter materials interspersed in it. \u201cSome stones appear mottled by brighter material that occurs as veins and crusts,\u201d the authors write. The largest piece is about 3.5 cm long, but much of it is dust. Stones with hummocky morphologies have the lowest densities, and mottled stones have the highest densities. <\/p>\n \u201cSome of the high-reflectance phases have a hexagonal crystal habit, whereas others appear as clusters of small spheres, platelets, and dodecahedral forms,\u201d the authors write. The collection also contains some individual pieces that are highly reflective. <\/p>\n Overall, the material is grouped into three categories: <\/p>\n Representative samples were also analyzed at other institutions in the US using different instruments including a plasma mass spectrometer, an infrared spectrometer, and an X-ray computer tomographer. These examinations revealed other information, like particle densities and elemental abundances. In particular, it contains isotopic information for hydrogen, carbon, nitrogen, and oxygen. It also compares these abundances to those of other asteroids. <\/p>\n But what jumps out from this initial analysis is the sample\u2019s serpentine and other clay minerals. Their presence is similar to what\u2019s found on Earth\u2019s mid-ocean ridges, where Earth\u2019s mantle encounters water. <\/p>\n On Earth, contact between mantle material and ocean water also creates clays and other minerals like carbonates, iron oxides, and iron sulphides. These were also found in the Bennu sample. <\/p>\n But one finding stands out among the rest: water-soluble phosphates. These compounds are found throughout Earth\u2019s biosphere and are an important component of biochemistry. <\/p>\n JAXA\u2019s Hayabusa 2 mission found a similar phosphate in its sample from asteroid Ryugu. But the phosphate from Bennu is different. Unlike any other asteroid sample, it has no inclusions and different-sized grains. The magnesium sodium phosphate in the Bennu sample suggests a watery past. <\/p>\n \u201cThe presence and state of phosphates, along with other elements and compounds on Bennu, suggest a watery past for the asteroid,\u201d Lauretta said. \u201cBennu potentially could have once been part of a wetter world. Although, this hypothesis requires further investigation.\u201d<\/p>\n In their paper, the authors outline several hypotheses for Bennu\u2019s past. One of them states that \u201c\u2026 the dominant lithologies on Bennu\u2019s surface have mineralogical, petrological, and compositional properties closely resembling those of the most aqueously altered carbonaceous chondrites.\u201d<\/p>\n The Bennu sample also shows that the asteroid is chemically primitive, meaning it has remained largely unchanged since its formation. The rocks have not melted and resolidified since their initial creation. The asteroid\u2019s elemental properties also mirror that of the Sun. <\/p>\n \u201cThe sample we returned is the largest reservoir of unaltered asteroid material on Earth right now,\u201d Lauretta said.<\/p>\n The initial research also shows that Bennu is rich in carbon and nitrogen, critical clues to the asteroid\u2019s origins. These chemicals also play a role in the appearance of life, adding to the intrigue. <\/p>\n \u201cThese findings underscore the importance of collecting and studying material from asteroids like Bennu \u2013 especially low-density material that would typically burn up upon entering Earth\u2019s atmosphere,\u201d said Lauretta. \u201cThis material holds the key to unraveling the intricate processes of solar system formation and the prebiotic chemistry that could have contributed to life emerging on Earth.\u201d<\/p>\n Harold Connolly is a co-author of the study and the mission sample scientist who leads the Sample Analysis Team. He\u2019s also a professor at Rowan University in Glassboro, New Jersey, and a visiting research scientist at UArizona. \u201cThe Bennu samples are tantalizingly beautiful extraterrestrial rocks,\u201d Connolly said. \u201cEach week, analysis by the OSIRIS-REx Sample Analysis Team provides new and sometimes surprising findings that are helping place important constraints on the origin and evolution of Earthlike planets.\u201d<\/p>\n And this is really just the beginning. With these evaluations in hand and the sample catalogued, research scientists around the world will request samples for their own research. <\/p>\n Further secrets will be revealed. <\/p>\n\n
\n
![\"The](\"https:\/\/www.universetoday.com\/wp-content\/uploads\/2024\/06\/Bennu-sample-3-types-1-921x1024.jpg\")
![\"Earth's](\"https:\/\/www.universetoday.com\/wp-content\/uploads\/2022\/04\/Mid-ocean_ridge_cut_away_view-1024x350.png\")
![\"This](\"https:\/\/www.universetoday.com\/wp-content\/uploads\/2024\/06\/Bennu-sample-phosphate.jpg\")
![\"This](\"https:\/\/www.universetoday.com\/wp-content\/uploads\/2024\/06\/Bennu-reflected-and-UV.jpg\")
Like this:<\/h3>\n