LOS ANGELES -- A space telescope has detected signs of water on the largest object in the asteroid belt.

A team led by the European Space Agency noticed water plumes spewing from two regions on Ceres, a dwarf planet about the size of Texas. The source of the water is still a mystery. There may be layer of ice below the surface that gets heated or the plumes could come from ice volcanoes.

There are only a few other objects in the solar system known to have active plumes of water.

The observations appear in Thursday's issue of Nature.

NASA's Dawn spacecraft is on its way to visit Ceres next year. It won't be in the best position to see any plumes but its instruments can detect water.