DAWN Spacecraft is Currently Approaching its First Target

Dr. Mike Gaffey and Vishnu Reddy attended a meeting of the DAWN Mission Science Team in Germany in mid-May. The DAWN spacecraft is currently approaching its first target, the main belt asteroid (4) Vesta. The DAWN spacecraft will go into orbit about Vesta on July 17, and remain in orbit for nearly a year, mapping the surface structures and composition, before it proceeds on to its second target, the asteroid (1) Ceres. Vesta is the second largest asteroid (diameter ~ 550 km) and has a surface composition produced by volcanic activity very early in its history. The type of volcanic rocks (basaltic) on its surface indicate that Vesta was never struck hard enough to blow it apart, unlike the vast majority of asteroid parent bodies. Dr. Gaffey and Dr. Reddy is will be analyzing the spectra returned by the Italian Visible Infrared (VIR) Spectrometer aboard the DAWN Spacecraft to determine minerallogy, and will be collaborating with the German Max Planck imaging team to map out the surface composition of Vesta. The meeting was hosted by Germany’s Max Planck Institute, which provided the camera system on the DAWN spacecraft. The meeting was held in the city of Nördlingen, which is situated near the center of the 24 km wide Ries Basin, a fourteen million year old impact crater. Dr. Gaffey participated in a field trip to several outcrops of the impact debris (suevite – try Google) that filled the original crater. The suevite deposits are mined for construction material, and the cathedral in Nördlingen is build out of blocks of this suevite. Dr. Gaffey has a chunk of the suevite on his desk.