Is Bennu from an ocean world?

Surprise! (again)

Asteroid Bennu continues to reveal the unexpected. A new #OSIRISREx paper explains how its dust holds essential components for life and how the sample mirrors a type of rock found at mid-ocean ridges on Earth. Read more: https://t.co/I8Cez2HPs0 pic.twitter.com/4q8ep6DRLa

— NASA Astromaterials (@Astromaterials) July 2, 2024

NASA’s OSIRIS-REx mission has revealed significant findings from the asteroid Bennu, particularly the discovery of magnesium-sodium phosphate in the samples returned to Earth. This discovery has several implications:

Unexpected Mineral Composition:

• The presence of magnesium-sodium phosphate was surprising because it was not detected by the spacecraft’s remote sensing instruments while at Bennu.
• The phosphate found in Bennu’s samples is unusually pure and has a large grain size compared to similar findings in other meteorite samples.

Implications for Bennu’s Origin:

• The presence of phosphates suggests that Bennu might have originated from a primitive ocean world, indicating a potentially watery past for the asteroid.
• This hypothesis is supported by the detection of other water-bearing minerals like serpentine and smectite, which are typically found at mid-ocean ridges on Earth.

Astrobiological Significance:

• Phosphates are essential for Earth’s biochemistry, and their presence on Bennu raises questions about the asteroid’s past geochemical processes and its potential to harbor life-essential compounds.
• The sample also contains carbon, nitrogen, and organic compounds, which are crucial for life, providing insights into the chemical processes that could have led to the emergence of life on Earth.

Broader Scientific Impact:

• The findings underscore the importance of studying asteroids like Bennu to understand the complexities of solar system formation and prebiotic chemistry.
• The analysis of Bennu’s samples is expected to continue, with portions distributed to labs worldwide for further study, potentially yielding more intriguing discoveries about the solar system’s history and the origins of life on Earth.

Overall, the discovery of magnesium-sodium phosphate in Bennu’s samples has provided new insights into the asteroid’s history and composition, suggesting a more complex and potentially watery past than previously understood.

References:

https://www.sciencedaily.com/releases/2024/06/240626151925.htm

https://source.wustl.edu/2024/06/surprising-phosphate-finding-in-asteroid-sample/

https://www.space.com/nasa-osiris-rex-sample-return-phosphate-ocean-world

https://www.universetoday.com/167594/asteroid-samples-were-once-part-of-a-wetter-world/

https://science.slashdot.org/story/24/06/27/0420228/phosphate-in-nasas-osiris-rex-asteroid-sample-suggests-ocean-world-origins