Astronomers today announced that water vapor has been detected around Ceres. Ceres is the largest object in our solar system’s asteroid belt and has been classified as a dwarf planet, like Pluto.

The discovery is the first time water vapor has been detected around an object in the asteroid belt. The findings, published in the journal Nature, could provide significant data on how our solar system formed. The water vapor on Ceres was detected using the European Space Agency’s (ESA) Herschel space observatory.

“Herschel’s discovery of water vapour outgassing from Ceres gives us new information on how water is distributed in the Solar System,” said Göran Pilbratt, a Herschel project scientist at ESA. “Since Ceres constitutes about one fifth of the total mass of asteroid belt, this finding is important not only for the study of small Solar System bodies in general, but also for learning more about the origin of water on Earth.”

Astronomers currently believe that Ceres has some ice on its surface, and these new observations show that nearly all of the water vapor detected on Ceres is coming from two locations on its surface. These regions are slightly darker than average for Ceres’ surface, indicating that they may absorb more sunlight, leading to water vapor through a process called sublimation. Another hypothesis holds that cryovolcanoes on Ceres’ surface may be spewing water vapor.

“We estimate that approximately 6 kg of water vapour is being produced per second, requiring only a tiny fraction of Ceres to be covered by water ice, which links nicely to the two localised surface features we have observed,” said Laurence O’Rourke, co-author of the paper and a principal investigator for the Herschel program.

Image via ESA/ATG medialab