A 12TB archive of Steam builds from 2003 to 2013 exposes Valve's lost Half-Life 2: Episode 3, the camera-driven F-Stop game, and years of untouched third-party prototypes.

The new infrared observatory will map the entire sky in 102 colors, probing cosmic inflation and the origins of water.

A new NASA observatory will probe the universe's accelerating expansion and hunt for exoplanets, with launch set for Sunday.