July 20, 1976: Landing on the red planet

An international fleet of five Mars orbiters and two rovers will have ringside seats when a mountain-size comet streaks by on Oct. 19, passing within a scant 87,000 miles of the red planet at a blistering 126,000 mph.

VIDEO: By the light of a waning moon, the space shuttle Atlantis returned to Earth on July 21, dropping out of predawn darkness to close out NASA’s 135th and final shuttle voyage, a long-awaited – and long-dreaded – milestone marking the end of an era for American manned space flight. (Membership Required)

The discovery of intermittent flows of liquid water on Mars, announced with great fanfare Monday, makes the red planet the leading candidate for the near-term discovery of extraterrestrial life in the form of fossilized microbes or even existing microorganisms, NASA’s chief scientist told lawmakers Tuesday.