The Brightest Spot on Ceres
Explanation:
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.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
