Astronomers have discovered water vapor steaming off the mysterious little planetoid Ceres — and the discovery could have fascinating implications for the evolution of our solar system.

more fresh water than on earth

Using the Herschel Space Observatory, Michael Kuppers, a planetary scientist with the European Space Agency, and his team were able to look for

the chemical fingerprint of water molecules. They spotted water

coming off Ceres at a rate of about 13 pounds per second

— and the scientists think there could be so much

ice packed in the dwarf planet's mantle that its

melted contents would add up to more

fresh water than we have

on Earth.

why is ceres so wet? It turns out Ceres may not be native to this part of the solar system. It probably originated beyond the "snow line" — that imaginary boundary in the solar system beyond which water ice can exist in space. Icy comets are the usual suspect for having brought water to Earth, but it could just as well have been an asteroid, Kuppers said. NASA's Dawn spacecraft will reach Ceres in 2015 and give scientists more evidence about the solar system's history.

ceres' fall from grace Before Pluto's fall from planetary grace, there was Ceres. It's either the largest asteroid or the smallest dwarf planet — but for a few glorious decades in the 1800s, it was a full planet. Ceres sits in the asteroid belt between Mars and Jupiter — and it's the only dwarf planet in the inner solar system. The 590-mile-wide Ceres lost its title when astronomers realized that it wasn't alone: It was sitting in a vast field of asteroids.

Los Angeles Times