NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) spacecraft has found signs of water locked inside asteroid Bennu.
Asteroid Bennu is too small to have ever hosted liquid water, but this finding does indicate that liquid water was present at some time on Bennu’s parent body, a much larger asteroid.
Data obtained from spacecraft’s two spectrometers OSIRIS-REx Thermal Emission Spectrometer (OTES) and OSIRIS-REx Visible and Infrared Spectrometer (OVIRS) have revealed the presence of hydroxyl molecules that contain oxygen and hydrogen atoms bonded together.
These hydroxyl groups exist globally across asteroid in water-bearing clay minerals, indicating that at some point Bennu’s rocky material interacted with water.
Asteroid Bennu is near-Earth carbonaceous asteroid about the size of a small mountain in the Apollo group. It was discovered in September 1999 by the LINEAR Project.
Asteroid Bennu is one of the oldest known asteroids which is considered as a remnant from early in the formation of the solar system and orbits close to Earth’s path around the Sun.
Asteroid Bennu is a carbon-rich asteroid and believed to be the type of asteroids that may have chemical building blocks of life, along with lots of water.
So, analysis of a returned sample from it could help to reveal key insights about the early solar system and the origin of life on Earth. It is a potentially hazardous asteroid and there is a very slight chance it could strike into Earth in the late 22nd century.