As the Dawn spacecraft zeroes in on the dwarf planet Ceres in our solar system’s cluttered asteroid belt, it has beamed back a surprising and puzzling image of not one, but two bright spots shining up from the surface.
This distant image has scientists salivating at what other juicy nuggets lie in wait when Dawn begins orbiting Ceres on March 6. The snapshot, taken on February 19 from about 29,000 miles away from the dwarf planet, shows two spots reflecting light from the middle of a large crater. Already, scientists are running through the possibilities.
Here’s Chris Taylor, writing for Mashable:
The most obvious contender is ice, although ice would reflect more than 40% of all light hitting it. The difference may be accounted for by the resolution limit of Dawn’s camera at this distance. Scientists have previously detected water vapor coming from the surface of the dwarf planet, making ice — a more likely option.
Other speculations include the byproducts of an ice volcano or particularly salty deposits. This isn’t the first time mysterious spots have been seen on Ceres; back in 2004, the Hubble Space Telescope snapped images of a similar curiosity on the dwarf planet.
NASA hopes that Dawn ’s studies of Ceres will help decipher the processes of planet formation. Its development was interrupted by Jupiter’s massive gravitational forces, freezing it in time. The tiny rock is just a fraction the size of our moon, and since it hasn’t changed much since the birth of our solar system, it could also be an ideal window into the birth of our solar system.
Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA