Of all the dwarf planets in all the asteroid belts, Ceres might be one of the more mysterious,
a status that seems to persist no matter what we learn about it.
Hey guys!
Amy bringing out some space today on DNews!
Ceres, the planet turned asteroid turned dwarf planet has quickly become everyone’s favourite
little body thanks to NASA’s Dawn mission and some bright spots the spacecraft has spotted
that continue to baffle scientists.
A couple of months ago when Dawn was still about 29,000 miles (46,000 kilometers) away
from Ceres, the images returned from the spacecraft revealed two bright spots on the dwarf planet’s
surface.
There was a lot of speculation about what the spots might be ranging from evidence of
volcanic activity to ice deposits, but they were ultimately too small to resolve.
The mystery remained intact as Dawn approached for a closer look.
A new explanation surfaced after more images were processed showing the spots continued
to glow well after that region of the planet had turned away from the Sun and was bathed
in shadow.
The evidence then pointed to ice plumes, jets of ice shooting out of the planet’s subsurface
glowing high above the surface in the reflected sunlight.
Then on March 6, Dawn went into orbit around Ceres and got its first up close look at the
spots scientists expected would be windows into the dwarf planet’s chemical and physical
composition.
Instead, the mystery only deepened.
The two spots are actually just two of a dozen or so identified areas on the dwarf planet’s
surface characterized by extreme brightness, and they all behave differently.
Using Dawn’s thermal camera, mission scientists found that Spot 1 is colder than its immediate
surroundings.
Its companion spot, Spot 5, on the other hand, is warmer than the surrounding area.
Which means they’re unlikely to be the same thing.
Current theories range from the spots being a sign of ice to something called “hydrated
minerals,” which is water that isn’t quite ice but that has been absorbed by minerals.
But ice is pretty unlikely; Ceres is just close enough to the Sun that ice wouldn’t
really be stable on its small surface.
And it’s not the only mystery surrounding Ceres.
Dawn previously visited Vesta, another major body in the asteroid belt.
Drawing a comparison with a like object, Ceres has far fewer craters than scientists studying
it think it should have.
As Dawn makes more observations of the little dwarf planet, we’re sure to unpack the ongoing
mystery of the bright spots and learn about its composition and temperature.
But in the meantime, Ceres’ status as an embryonic planet that never fully formed will
remain likely until evidence says otherwise.
Are you guys excited to see what Dawn learns about Ceres in the coming months?