NASA’s OSIRIS-Rex probe will take a survey sample on the surface of the asteroid Bennu before returning to Earth. Recently, scientists on the mission presented new discoveries about the surface matter, geological features and dynamic history of the asteroid Bennu. The researchers say they suspect that samples sent back to Earth from asteroids may differ from any meteorite samples we collect on Earth.
A paper led by Amy Simon from Goddard’s Space Flight Center shows that carbon-containing organic matter is widespread on the asteroid’s surface, including major mission landing points. The landing point is where OSIRIS-REx will conduct its first sample acquisition attempt on October 20. The results of this study show that hydration minerals and organic matter are expected to exist at the landing point. The researchers hope that studies of organic molecules will help answer questions about the origin of water and life on Earth.
Scientists are optimistic that the richness of carbon-containing material means that spacecraft will sample it and send it back to Earth. The team also found bright veins in many boulders and rocks on the asteroid’s surface, which appear to be carbonates. Some of the rocks are located near Nightingale Crater, suggesting that carbonates may be present in the returned samples.
The presence of carbonate led the team to believe that Benu’s parent asteroid probably had a broad hydrothermal system in which the water interacted with rocks on the mother and altered the rocks of the mother. The veins in some of the asteroid’s boulders are several feet long and inches thick, which scientists say validates the asteroid-sized hydrothermal system on the mother.
The scientific team also found that rocks near the landing site of the OSIRIS-Rex probe were exposed to harsh space environments. This means that “Benu” will collect and return the most primitive material on the asteroid. Another paper distinguishes between two main types of boulders on the asteroid’s surface, dark and rough, and bright and smooth. They believe that these two different types of rocks may have formed at different depths in the asteroid’s parent. Dark and rough porous rocks are destroyed as they enter the Earth’s atmosphere and may never have been seen in meteorite samples collected on Earth.