NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) spacecraft has found water locked inside asteroid Bennu. 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.
It launched in September 2016 is NASA’s first asteroid sampling mission i.e. it will survey surface, collect the sample and deliver it safely back to Earth. It had reached its destination Bennu asteroid in December 2018 after travelling through space for more than two years and travelling over two billion kilometres. Samples returned by the mission to Earth in 2023 will enable scientists to find new information about the history and evolution of our solar system.
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.