After the speech, Mr Grunsfeld fielded a question from Jim Bell, a planetary scientist and current president of the Planetary Society, a space advocacy organisation in California.
Created by planetary scientist Emily Lakdawalla of The Planetary Society, this montage captures every comet and asteroid that's had its picture taken close-up by a visiting spacecraft.
The restoration is "a good opening salvo that many in the planetary community support," says Jim Bell, president of the Planetary Society, an advocacy organization based in Pasadena, California, and a planetary scientist at Arizona State University, Tempe.
To assist in promoting planetary exploration, Murray, Sagan and Friedman founded the Planetary Society, a nonprofit organization whose mission was to support and lobby for deep space exploration.
The writer is executive director emeritus, the Planetary Society.
In 1980 Sagan cofounded the Planetary Society, an international nonprofit organization for space exploration.
The gathering was organized by the Planetary Society, a group based in Pasadena with 80,000 members.
"Think centuries or millennia, not decades," said Dr. Dyson, who also said he approved of the Planetary Society project.
He has also worked as a visiting professor at Cornell and an executive at the Planetary Society.
Jim Bell, president of the Planetary Society, who is not involved in the mission, said searching for life on another planet is difficult.
