Research at the USC Viterbi School of Engineering has revealed new evidence for the occurrence of ground ice on the protoplanet Vesta.
[...] The team used a special technique called "bistatic radar" on the Dawn spacecraft to explore the surface texture of Vesta at the scale of a few inches. On some orbits, when the spacecraft was about to travel behind Vesta from Earth's perspective, its radio communications waves bounced off Vesta's surface, and mission personnel on the ground at NASA's Jet Propulsion Laboratory (JPL) received the signals back on Earth.
Vesta was thought to be a dry body [inverse.com]:
Now, thanks to the latest round of results from NASA's Dawn mission, we have learned Asimov was right about Vesta all along. As researchers at the University of Southern California write in Tuesday's Nature Communications [nature.com] [open, DOI: 10.1038/s41467-017-00434-6] [DX [doi.org]], the probe discovered unusually large smooth regions on the otherwise craggy asteroids. The researchers linked these with higher hydrogen concentrations, which in turn strongly suggest the presence of ground ice on Vesta.
"It was believed to be a dry body," NASA researcher Essam Heggy, Ph.D. [nasa.gov] tells Inverse, saying previous evidence for water on Vesta had, at best, been ambiguous. Dawn's findings erase those ambiguities. It's just the latest of many findings in recent years showing that water and ice are damn near everywhere in the solar system, adding Vesta to a list that already includes Mars, the moons Europa and Enceladus, and its fellow asteroid Ceres. "The more we search, the more we find ice and water in the solar system," says Heggy, "and the more we realize water is not unique to our planet."