The
Brightest Spot on Ceres
From NASA's Astronomy
Picture of the Day
Dwarf planet Ceres is the largest object in
the Solar System's main asteroid belt with a diameter of about 950
kilometers.
Exploring Ceres from orbit since March, the Dawn spacecraft's
camera has revealed about 130 or so mysterious bright spots, mostly associated
with impact craters scattered around the small world's otherwise dark
surface.
The brightest one is near the center of the
90 kilometer wide Occator Crater, seen in this dramatic false color view combining near-infrared and
visible light image data.
A study now finds the bright
spot's reflected
light properties are probably most consistent with a type of magnesium sulfate
called hexahydrite.
Of
course, magnesium sulfate is also known to Earth dwellers as epsom salt.
Haze
reported inside Occator also suggests the salty material could be left over as
a mix of salt and water-ice sublimates on the surface.
Since
impacts would have exposed the material, Ceres' numerous and widely scattered
bright spots may indicate the presence of a subsurface shell of ice-salt mix.
In
mid-December, Dawn will begin taking observations from
its closest Ceres mapping orbit.
Image Credit: NASA, JPL-Caltech, UCLA,
MPS/DLR/IDA
