Good afternoon, Earthlings!
This week is all about Ceres and the recent NASA Dawn mission to produce high resolution images of the surface of our closest and largest asteroid (about 590 miles in diameter). What makes Ceres such an interesting mystery before is the lack of meteorite analogues. That is, we have no meteorite evidence to link it to the Ceres surface!
The Dawn spacecraft's mission is to observe the surface geology and compositions of Ceres. It launched in 2007 and arrived at Ceres on March 2015. Since then, images and data of the surface led to knowledge and more questions! We found ice mountains, eroded craters, and, of course…the "bright spots."
The infamous bright spots in the middle of one of Ceres' craters is still making planetary scientists scratch their heads and continually guess what this exposed white material could be. Theories range from explosive water-ice geysers to rock-ice mixtures to possibly salt and ice! These very reflective bright spots have been imaged numerous times and every time is no much closer to a guess than the previous image. More images then showed that there are over 130 bright spot areas!
Even more evidence from the images have showed some evaporation of water to form very thin hazed over certain craters, such as Occator crater- the crater with the larger bright spots. But what is causing this to happen? That is still a mystery, too. Another surprise on the surface of Ceres is that the surface is rich with ammonia-clays! The presence of ammonia suggests that the large asteroid body did not form in its current position between Mars and Jupiter in the asteroid belt, but rather in the outer solar system where ammonia and other complex compounds reside, and (somehow) this celestial body migrated inward.
The puzzlement and excitement continue as the Dawn spacecraft continues to take images!
Tune in next week for insight into the NASA K2 mission and an update on the Pluto Chamber in the lab!