By Bob King
We don’t know exactly what those mysterious white spots on Ceres are
yet, but we’re getting closer to an explanation. Literally. The latest
images from the Dawn spacecraft taken a mere 8,400 miles from the dwarf
planet Ceres reveal that the pair of spots are comprised of even more
spots.
“Dawn scientists can now conclude that the intense brightness of
these spots is due to the reflection of sunlight by highly reflective
material on the surface, possibly ice,” said Christopher Russell,
principal investigator for the Dawn mission from the University of
California, Los Angeles.
Dawn recently concluded its first science orbit, making a 15-day full
circle around Ceres while gathering data with its suite of science
instruments. This past Saturday, May 9, its ion engine fired once again
to lower the spacecraft to its second science orbit which it will enter
on June 6. On that date, the probe will hover just 2,700 miles (4,400
km) above the dwarf planet and begin a comprehensive mapping of the
surface. Scientists also hope the bird’s eye view will reveal clues of
ongoing geological activity.
There’s no doubt a lot’s been happening on Ceres. One look at all
those cracks hint at either impact-related stresses some kind of crustal
expansion. Geological processes may still make this little world rock
and roll.
Fortunately, we won’t have to wait till next month for more photos.
NASA plans to pause the probe twice on the way down to shoot and send
fresh images.