Explore astronomy, from the latest trip to the International Space Station to alien planets outside our solar system.
Video: Leslie Kean describes the hard evidence of UFOs and calls for more investigation into them. Plus: Did you know there was a UFO at Chicago's O'Hare Airport?
This adjustment should help astronomers better understand how the sun and planets formed.
Scientists reconstruct a story of cataclysmic violence in the Southwest.
Cracks in the moon's crust that formed as the interior cooled and shrunk over the last billion years indicate that the surface has shrunk too.
The two stamps, which will be offered as an attached pair, are tentatively scheduled for release next spring.
NASA is seen as the first stepping stone to ultimately get to that 'Star Wars' level.
Coincidentally, opposition also fell on Aug. 20, 1846.
Proposed telescope will look for habitable exoplanets and study the nature of dark energy.
Video: MSNBC's Chris Jansing talks with NASA astronauts Mark and Scott Kelly, who will become the first identical twins in space at the same time.
Long-term space flight so weakens fitness that an astronaut going to Mars may lose up to half the power in key muscles in the course of the mission.
Senator Bill Nelson's legislation would give tax breaks to those who invest in space ventures to offset job losses from the end of the shuttle program.
Experts think Van Gogh and Bach would be more appealing than Newton or Einstein.
The International Space Station has been operating on half its normal cooling capability since the pump failed July 31.
Robonaut 2 is scheduled to arrive at the International Space Station in November, fields Twitter questions in the meantime.
Previous spacewalk bid to restore full cooling to orbiting lab had been thwarted by large ammonia leak.
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Science journalist blogs about humans and other wildlife.