Original air date: Thursday, July 16, 2015. July 2015 marks the 50th anniversary of Mariner 4, the first spacecraft to successfully fly by the planet Mars. Scientists .
more at: Mariner 4 was the first spacecraft to fly by Mars and send home close-up images. Find out how the .
Famed astronomer and Cornell University scientist Carl Sagan takes the viewer to the Red Planet in this circa 1972 official NASA film, “Mars: The Search Begins.
