Surprising phosphate finding in NASA’s OSIRIS-REx asteroid sample

Scientists have eagerly awaited the chance to dig into the 4.3-ounce (121.6-gram) pristine asteroid Bennu pattern collected by NASA’s OSIRIS-REx (Origins, Spectral Interpretation, Useful resource Identification, and Safety—Regolith Explorer) mission because it was delivered to Earth final fall. They’ve hoped the fabric would maintain secrets and techniques of the solar system’s previous and the prebiotic chemistry which may have led to the origin of life on Earth.

An early evaluation of the Bennu pattern, published in Meteoritics & Planetary Science, demonstrates that this pleasure was warranted.

The OSIRIS-REx Pattern Evaluation Group discovered that Bennu incorporates the unique substances that shaped our solar system. The asteroid’s dust is wealthy in carbon and nitrogen, in addition to organic compounds, all of that are important elements of life as we all know it. The pattern additionally incorporates magnesium-sodium phosphate, which was a shock to the analysis staff, as a result of it wasn’t seen within the distant sensing knowledge collected by the spacecraft at Bennu. Its presence within the pattern hints that the asteroid may have splintered off from a long-gone, tiny, primitive ocean world.

A phosphate shock

Evaluation of the Bennu pattern unveiled intriguing insights into the asteroid’s composition. Dominated by clay minerals, notably serpentine, the pattern mirrors the kind of rock discovered at mid-ocean ridges on Earth, the place materials from the mantle, the layer beneath Earth’s crust, encounters water.

This interplay does not simply lead to clay formation; it additionally offers rise to a wide range of minerals like carbonates, iron oxides, and iron sulfides. However essentially the most sudden discovery is the presence of water-soluble phosphates. These compounds are elements of biochemistry for all recognized life on Earth at this time.

Whereas an analogous phosphate was discovered within the asteroid Ryugu pattern delivered by JAXA’s (Japan Aerospace Exploration Company) Hayabusa2 mission in 2020, the magnesium-sodium phosphate detected within the Bennu pattern stands out for its purity—that’s, the dearth of different supplies within the mineral—and the dimensions of its grains, unprecedented in any meteorite pattern.

The discovering of magnesium-sodium phosphates within the Bennu pattern raises questions concerning the geochemical processes that concentrated these components and gives worthwhile clues about Bennu’s historic situations.

“The presence and state of phosphates, together with different components and compounds on Bennu, suggests a watery previous for the asteroid,” mentioned Dante Lauretta, co-lead writer of the paper and principal investigator for OSIRIS-REx on the College of Arizona, Tucson. “Bennu probably may have as soon as been a part of a wetter world, though this speculation requires additional investigation.”

“OSIRIS-REx gave us precisely what we hoped: a big pristine asteroid pattern wealthy in nitrogen and carbon from a previously moist world,” mentioned Jason Dworkin, a co-author on the paper and the OSIRIS-REx undertaking scientist at NASA’s Goddard Area Flight Middle in Greenbelt, Maryland.

From a younger solar system

Regardless of its potential historical past of interplay with water, Bennu stays a chemically primitive asteroid, with elemental proportions intently resembling these of the sun.

“The pattern we returned is the biggest reservoir of unaltered asteroid materials on Earth proper now,” mentioned Lauretta.

This composition affords a glimpse into the early days of our solar system, over 4.5 billion years in the past. These rocks have retained their authentic state, having neither melted nor resolidified since their inception, affirming their historical origins.

Hints at life’s constructing blocks

The staff has confirmed the asteroid is wealthy in carbon and nitrogen. These components are essential in understanding the environments the place Bennu’s supplies originated and the chemical processes that reworked easy components into advanced molecules, probably laying the groundwork for all times on Earth.

“These findings underscore the significance of gathering and learning materials from asteroids like Bennu—particularly low-density materials that will usually dissipate upon coming into Earth’s ambiance,” mentioned Lauretta. “This materials holds the important thing to unraveling the intricate processes of solar system formation and the prebiotic chemistry that might have contributed to life rising on Earth.”

What’s subsequent

Dozens extra labs in america and all over the world will obtain parts of the Bennu pattern from NASA’s Johnson Area Middle in Houston within the coming months, and lots of extra scientific papers describing analyses of the Bennu pattern are anticipated within the subsequent few years from the OSIRIS-REx Pattern Evaluation Group.

“The Bennu samples are tantalizingly lovely extraterrestrial rocks,” mentioned Harold Connolly, co-lead writer on the paper and OSIRIS-REx mission pattern scientist at Rowan College in Glassboro, New Jersey. “Every week, evaluation by the OSIRIS-REx Pattern Evaluation Group gives new and generally stunning findings which are serving to place essential constraints on the origin and evolution of Earth-like planets.”

Launched on Sept. 8, 2016, the OSIRIS-REx spacecraft traveled to near-Earth asteroid Bennu and picked up a pattern of rocks and dust from the floor. OSIRIS-REx, the primary U.S. mission to gather a pattern from an asteroid, delivered the pattern to Earth on Sept. 24, 2023.