Meet Carl Sagan, known for his research on extraterrestrial life! Follow Sagan's story as he theorizes on the temperature of Venus's surface, works with NASA to build the Mariner 2, Viking I, and Viking II probes, and creates the popular PBS program Cosmos. Infographics, historic photos, and a glossary enhance readers' understanding of this topic. Additional features include a table of contents, an index, a timeline and fun facts. Aligned to Common Core Standards and correlated to state standards. Checkerboard Library is an imprint of Abdo Publishing, a division of ABDO.