... Space Motions for the Draco and Sextans Dwarf Spheroidal Galaxies . Abstract . ... A Snapshot Survey of The Most Massive Clusters of Galaxies . ... The Sloan sky survey provides a powerful tool for identifying candidate galaxy-galaxy lenses; this program is using HST-ACS imaging to verify the nature of those candidates, and provide the angular resolution necessary to model the mass distribution. ... In the coming week, HST will observe the host star as part of two observational programs. ...