Countdowns
19 March 2011, 11:53 AM ET
Weightlessness changes a lot of the physical conditions we take for granted on Earth.
22 February 2011, 12:36 PM ET
Vote for your favorite innovators of the new digital space age.
06 January 2011, 10:38 AM ET
The universe is a weird place. Here's a look at some of the strangest things in the cosmos.
26 October 2010, 11:22 AM ET
From stellar fireworks caused by supernova explosions to invisible black holes, astronomers are gradually figuring out how stars work and what makes each variety unique. Many mysteries remain, however.
26 October 2010, 10:30 AM ET
Take a tour of the effect Sputnik, the world's first artificial satellite, has had on science 50 years after its launch.
25 October 2010, 06:31 PM ET
Our solar system's planets vary greatly in size, composition, temperature, chemistry and geology. Here are some notable extreme facts about the planets that orbit our Sun.
19 October 2010, 07:32 PM ET
The age of private spaceflight is almost upon us with a veritable fleet of new commercial spaceships rolling out to the launch pad. As NASA iconic space shuttles retire for good, here's a look at new private ships soon to be reality
06 January 2008, 02:07 PM ET
Humans have sent many missions, both manned and robotic, beyond our planet to explore our neighboring celestial bodies.
01 May 2006, 01:13 PM ET
As a longtime investigator of unusual phenomena, I have no doubt that UFOs exist.
07 July 2003, 04:00 PM ET
See questions and answers about the Columbia Accident Investigation Board's (CAIB) final report.