The discovery of water on other planets is of utmost importance for science and the exploration of other worlds as it is associated with the possible existence of life outside our planet. Thanks to ESA’s Herschel space observatory, water vapor has been found for the first time in an object in the asteroid belt, the dwarf planet Ceres.
It only has a diameter of 950 kilometers and yet it is the largest object in the asteroid belt, located between the orbits of Jupiter and Mars. Furthermore, this small planet, unlike most asteroids, is practically spherical. All these peculiarities make Ceres a very special planet and specially studied by astronomers.
Now they have just detected water vapor in its atmosphere and ice on its surface. As the lead author of the Nature paper, Michael Küppers, from ESA’s European Space Astronomy Center in Madrid, explains, “this is the first time that water has been detected in the asteroid belt, and it confirms that Ceres has an ice surface. and an atmosphere ”.
In fact, as scientists have been able to verify, practically all the vapor comes from only two points on its surface . The researchers’ calculations lead them to think that about 6 kg of water vapor is being produced per second, which would mean that only a small fraction of Ceres is covered in ice. In this regard, Laurence O’Rourke, co-author of the article, points out that “this hypothesis fits perfectly with the two specific regions that we have observed”.
These two vapor emission points are 5% darker than the rest of the surface, which means that they absorb more sunlight and should be warmer. This fact would favor the phenomenon of sublimation of water (the passage from the solid state of water directly to gas), as occurs in comets.
“ Herschel’s discovery gives us new data on the distribution of water in the Solar System . As Ceres constitutes approximately one fifth of the total mass of the asteroid belt, this discovery is not only important for the study of the smallest bodies in the Solar System, but also helps us to better understand the origin of water on our planet ” explains Göran Pilbratt, ESA Herschel Project Scientist.
In 2015, NASA’s Dawn mission is scheduled to arrive at Ceres to study its surface and observe in situ how water vapor emissions are produced and evolved.
