Initial Science Results from OSIRIS-REx Suggest the Presence of Water on Asteroid Bennu

Image credit: NASA/Goddard Space Flight Center/University of Arizona

In case you missed the press conference at the American Geophysical Union’s Fall Meeting (Washington, DC) last week, the OSIRIS-REx team reported their initial scientific findings on arriving at the asteroid Bennu. The OSIRIS-REx spacecraft, NASA’s first asteroid sample return mission, arrived at Bennu on December 3, and the science team has already recognized signs of water on its surface. The water is not liquid or ice, but is hydroxyl molecules (OH) bound into clay minerals. The hydroxyl was detected by its signatures in light reflected from, and emitted by, Bennu’s surface (from the OSIRIS-REx Visible and Infrared Spectrometer, OVIRS, and the OSIRIS-REx Thermal Emission Spectrometer, OTES, instruments, respectively). The presence of water-bearing minerals like clays suggests that water-rock interactions occurred on Bennu in the past and supports the hypothesis that asteroids and comets could have delivered water and organics to the early inner solar system. Organics have not yet been identified, but OSIRIS-REx will enter orbit on December 31 and will continue collecting observations prior to selecting a sample for return to Earth.

For more information, visit:

To see the press conference, visit: