The Darkened Cosmos: A Tribute to Carl Sagan
http://www.csicop.org/si/show/darkened_cosmos_a_tribute_to_carl_sagan/Article from the Skeptical Enquirer describing Sagan's major achievements, with tributes from his friends and colleagues.
Submitted in section: Astronomy: History: People: Sagan, Carl: The Darkened Cosmos: A Tribute to Carl Sagan