Astronomers have spotted water plumes on dwarf planet Ceres

We've observed water on Ceres. The largest object in the asteroid belt, you may remember Ceres as the round, rock-ice body that was considered for reclassification as a planet in the midst of Pluto's demotion. Astronomers observed the water in the form of vapor plumes, possibly issuing from volcano-like geysers on… » 1/22/14 6:00pm 1/22/14 6:00pm

Could giant asteroid Vesta actually be a planet?

For years, scientists have been calling Vesta an asteroid. Granted, it's a big asteroid — at 330 miles across, it's the second biggest in the solar system — but NASA's Dawn spacecraft recently got its closest look at Vesta yet, and according to Dawn's principle investigator Christopher Russel, astronomers have been… » 3/23/12 1:15pm 3/23/12 1:15pm