History of Carl Sagan

	Revision 15 . . November 19, 2001 4:22 pm by Chenyu
	Revision 14 . . (edit) November 10, 2001 5:23 am by MichaelTinkler [minor edit for style (no need for title & first name in next to last sentence)]

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Carl Sagan was a professor and lab director at Cornell University. He contributed to most of the unmanned space missions that explored our solar system. His idea was to add an unalterable and universal message on the spacecraft that could be understood by an extraterrestrial intelligence.

Carl Sagan was a professor and lab director at Cornell University. He contributed to most of the unmanned space missions that explored our solar system. His idea was to add an unalterable and universal message on the spacecraft that could be understood by an extraterrestrial intelligence. He was also well known for coauthor the paper that warned of the dangers of [nuclear winter]?.