Members of the audience look on as Dr. James L. Green, Director of Planetary Science at NASA, right, speaks with Dr. Robert Farquar, an executive for space exploration at KinetX Inc., during a symposium commemorating a quarter-century of comet discoveries, Friday, Sept. 10, 2010, in the Knight studio at the Newseum in Washington. The International Sun-Earth Explorer-3 (ISEE-3) spacecraft flew past the comet Giacobini-Zinner on Sept. 11, 1985 which established a foundation of discoveries that continue today. Photo Credit: (NASA/Paul E. Alers)