Ceres Rotating Image

Since NASA's Dawn spacecraft arrived in orbit at Ceres in March 2015, scientists have located more than 300 bright areas on Ceres. A new study in the journal Icarus divides Ceres' features into four categories. The first group of bright spots contains the most reflective material on Ceres, which is found on crater floors. All the bright material in Occator Crater is made of salt-rich material, which was likely once mixed in water.

More commonly, in the second category, bright material is found on the rims of craters, streaking down toward the floors. Impacting bodies likely exposed bright material that was already in the subsurface or had formed in a previous impact event.

Separately, in the third category, bright material can be found in the material ejected when craters were formed.

The mountain Ahuna Mons gets its own fourth category -- the one instance on Ceres where bright material is unaffiliated with any impact crater. This likely cryovolcano, a volcano formed by the gradual accumulation of thick, slowly flowing icy materials, has prominent bright streaks on its flanks.

So if you voted volcano, ice or salt deposit, you guessed right!