Scientists using the Herschel space observatory have made the first definitive detection of water vapor on the largest object in the asteroid belt, Ceres.
Plumes of water vapor are thought to shoot up periodically from Ceres when portions of its icy surface warm slightly. Ceres is classified as a dwarf planet, a solar system body bigger than an asteroid and smaller than a planet.
Herschel is a European Space Agency (ESA) mission with NASA contributions.
“This is the first time water vapor has been unequivocally detected on Ceres or any other object in the asteroid belt and provides proof that Ceres has an icy surface and an atmosphere,” said Michael Küppers of ESA in Spain, lead author of a paper in the journal Nature.
The results come at the right time for NASA’s Dawn mission, which is on its way to Ceres after spending more than a year orbiting the large asteroid Vesta. Dawn is scheduled to arrive at Ceres in the spring of 2015, when it will take the closest look ever at its surface.
Above is an artist’s conception of Ceres in the asteroid belt, which lies between the orbits of Mars and Jupiter.
For more on the discovery, see this NASA press release.