Originally published June 26, 2024 at NASA.gov. Edits by EarthSky.
- A sort of rock mirroring that discovered at Earthly mid-ocean ridges has been discovered through evaluation of the asteroid Bennu pattern returned by NASA’s OSIRIS-REx mission in September 2023.
- The magnesium-sodium phosphate discovered within the pattern hints that the asteroid might have splintered off from a small, historic, primitive ocean world.
- Japan’s Hayabusa2 mission additionally delivered an asteroid pattern again to Earth, in 2020. It got here from asteroid Ryugu, and it revealed an analogous phosphate.
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 spacecraft because it was delivered to Earth final fall. They hoped the fabric would maintain secrets and techniques of the solar system’s previous and the prebiotic chemistry that may have led to life on Earth. An early evaluation of the Bennu pattern demonstrates this pleasure was warranted. A sort of rock within the pattern hints that the asteroid might have splintered off from a long-gone, tiny, primitive ocean world.
The OSIRIS-REx Pattern Evaluation Group discovered that Bennu accommodates the unique components that shaped our solar system. The asteroid’s dust is wealthy in carbon and nitrogen, in addition to natural compounds, all of that are important elements for all times as we all know it. The pattern additionally accommodates magnesium-sodium phosphate, which was a shock to the analysis workforce, as a result of it wasn’t seen within the distant sensing information collected by the spacecraft at Bennu. Its presence suggests an ocean world origin.
The journal Meteoritics & Planetary Science printed this new work on June 26, 2024.
OSIRIS-REx is the primary U.S. mission to gather a pattern from an asteroid. It was launched on September 8, 2016. The spacecraft traveled to near-Earth asteroid Bennu and picked up a pattern of rocks and dust from the floor. It delivered the pattern to Earth on September 24, 2023.
The spacecraft is at present on its way to infamous asteroid Apophis, which it should attain in April, 2029, simply because the asteroid is sweeping previous Earth.
Asteroid Bennu pattern reveals 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 doesn’t simply end in clay formation; it additionally provides rise to a wide range of minerals like carbonates, iron oxides, and iron sulfides. However probably the most surprising discovery is the presence of water-soluble phosphates. These compounds are elements of biochemistry for all recognized life on Earth right this moment.
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 shortage of different supplies within the mineral — and the scale of its grains, unprecedented in any meteorite pattern.
The discovering of magnesium-sodium phosphates within the Bennu pattern raises questions in regards to the geochemical processes that concentrated these parts and supplies helpful clues about Bennu’s historic situations. Dante Lauretta, co-lead creator of the paper and principal investigator for OSIRIS-REx on the College of Arizona, Tucson, stated:
The presence and state of phosphates, together with different parts and compounds on Bennu, counsel a watery previous for the asteroid. Bennu doubtlessly might have as soon as been a part of a wetter world. Though, this speculation requires additional investigation.
Jason Dworkin, a co-author on the paper and the OSIRIS-REx challenge scientist at NASA’s Goddard House Flight Middle in Greenbelt, Maryland, stated:
OSIRIS-REx gave us precisely what we hoped: a big pristine asteroid pattern wealthy in nitrogen and carbon from a previously moist world.
From a younger solar system
Regardless of its potential historical past of interplay with water, Bennu stays a chemically primitive asteroid, with elemental proportions carefully resembling these of our sun. Lauretta stated:
The pattern we returned is the biggest reservoir of unaltered asteroid materials on Earth proper now.
This composition provides 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 historic origins.
Hints at life’s constructing blocks
The workforce has confirmed the asteroid is wealthy in carbon and nitrogen. These parts are essential in understanding the environments the place Bennu’s supplies originated, and the chemical processes that reworked easy parts into advanced molecules, doubtlessly laying the groundwork for all times on Earth. Lauretta stated:
These findings underscore the significance of amassing and finding out materials from asteroids like Bennu — particularly low-density materials that might usually fritter away upon getting into Earth’s environment.
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 the US and all over the world will obtain parts of the Bennu pattern from NASA’s Johnson House Middle in Houston within the coming months. And plenty of extra scientific papers describing analyses of the Bennu pattern are anticipated within the subsequent few years from the OSIRIS-REx Pattern Evaluation Group. Harold Connolly, co-lead creator on the paper and OSIRIS-REx mission pattern scientist at Rowan College in Glassboro, New Jersey, stated:
The Bennu samples are tantalizingly stunning extraterrestrial rocks. Every week, evaluation by the OSIRIS-REx Pattern Evaluation Group supplies new and typically shocking findings which can be serving to place essential constraints on the origin and evolution of Earth-like planets.
Backside line: NASA’s OSIRIS-REx mission delivered a pattern of asteroid Bennu to Earth in late 2023. Evaluation of the pattern exhibits a kind of rock mirroring that discovered at Earthly mid-ocean ridges.
