With a diameter of 945 kilometers, the thirty third largest body in our solar system rules the asteroid belt between Mars and Jupiter. Spinning on axis in a nine hour day, rounded by its own gravity, comprised of rock and ice – a third of the asteroid belt’s mass, answers to the name Ceres.
NASA’s Dawn Mission reached Ceres in March 2015, discovery of “bright spots” left science scrambling for answers. Residing in Occator Crater, the largest revealed characteristics without explanation. Evidence of salt deposits, indication of never imagined “activity” in an asteroid? Dawn couldn’t tell, but astronomer Paulo Molaro at La Silla in Chile shed sunlight on Ceres.
“… when the spots inside the Occator crater are on the side illuminated by the sun they form plumes that reflect sunlight very effectively. These plumes then evaporate quickly, lose reflectivity and produce the observed changes. This effect, however, changes from night to night, giving rise to additional random patterns, on both short and longer timescales.
If this interpretation is confirmed Ceres would seem to be very different from Vesta and the other main belt asteroids. Despite being relatively isolated, it seems to be internally active.
Ceres is known to be rich in water, but it is unclear whether this is related to the bright spots. The energy source that drives this continual leakage of material from the surface is also unknown.”