Richard Branson's Virgin Galactic is on track to begin commercial passenger spaceflights before the end of 2018, the company's chief executive said.
NASA is years away from having new spacesuits for its deep-space astronauts despite spending nearly $200 million on three separate development efforts over the past decade.
Comet 45P/Honda-Mrkos-Pajdusakova, returning to the inner solar system after more than five years, will be visible this week with binoculars or a small telescope.
The unusual agreement could act as insurance for NASA's access to the International Space Station should commercial launches be delayed.
The new weapon is designed to find, track and destroy multiple enemy warheads — even if they are accompanied by decoys.
The SETI community is rethinking how reports of extraterrestrial life should be shared with the public.
Revamped after a steering system failure, NASA's orbiting telescope still is contributing to the growing inventory of planets beyond our solar system.
The Milky Way may be home to some 3,000 extraterrestrial civilizations but the vast distances between our galactic cousins will make contact extremely rare, a new study concludes.
The chemistry of life better matches that found in volcanic vents rather than the sea, as Darwin predicted.