Explore astronomy, from the latest trip to the International Space Station to alien planets outside our solar system.
Canadian astronaut Chris Hadfield will perform scientific experiments, robotics tasks and technology demonstrations.
Hawking said the Big Bang is merely the consequence of the law of gravity.
Weather postpones liftoff of $63,400 prototype, financed mostly by 2,000 individual sponsors and 20 companies.
Some insist a mysterious photograph shows machinery on Mars despite complete lack of credible evidence.
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?
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.
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.
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.
The mission, which sounds like the theme of 'Deep Impact', would take off in 2106 to take samples of the dangerous asteroid.
Activist and author blogs about politics, energy and Earth's resources.
Science journalist blogs about humans and other wildlife.