1. Department of Astronomy, Cornell University, Ithaca, NY 14853, USA
2. Universities Space Research Association, NASA/Armstrong Flight Research Center, 2825 East Avenue P, Palmdale, CA 93550, USA
3. Department of Physics & Astronomy, Ithaca College, Ithaca, NY 14850, USA
4. Universities Space Research Association, NASA Ames Research Center, MS 211-3, Moffett Field, CA 94035, USA
5. NASA Ames Research Center, Moffett Boulevard, Moffett Field, CA 94035, USA