NASA finds stardust older than the solar system in asteroid Bennu
OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer) is a NASA mission that launched in 2016. The mission collected samples from the asteroid Bennu, among other activities and objectives.
Scientists believe asteroids regularly collided with young planets during the planets’ formative years. As a result, there was a chance these asteroids delivered water and other ingredients for life to Earth during impact. That was OSIRIS-REx’s mission. It collected samples from Bennu’s surface on October 20, 2020. Three different research groups have now found some interesting details about those samples.
Given that Bennu was formed from a much larger asteroid, one of the groups focused on tracing the origins of Bennu’s ancestor. They found components older than even the solar system. Ann Nguyen, one of the co-leads of the papers, reported:
“We found stardust grains with compositions that predate the solar system, organic matter that likely formed in interstellar space, and high temperature minerals that formed closer to the Sun.”
Another group discovered that the materials making up Bennu underwent several changes over time as they reacted with water. Their analysis suggests that Bennu’s ancestors collected ice and dust. The ice melted, and the liquid then mixed with the dust to form the parts of Bennu observed.
The third group found impact melts on the surface of the samples from Bennu. This suggests that the asteroid was hit several times by micrometeorites. Since asteroids have no atmosphere, surface weathering from the effects of micrometeorites and hot, blazing solar wind is expected. But on Bennu, it is happening at an incredibly fast rate.
OSIRIS-REx is on its way to asteroid Apophis under a new name — OSIRIS-APEX. It will likely observe Apophis together with the Ramses mission. Asteroids are like a time capsule. Scientists are using them to get a clear picture of how the solar system formed about 4.5 billion years ago.
