Even robots like to have fun. NASA's rover on Mars showed off its playful side by snapping a picture of its own shadow. It's the latest self-portrait since the rover, named Opportunity, landed on the red planet in 2004.

The world's first private supply ship flew tantalizingly close to the International Space Station on Thursday, acing a critical test in advance of the actual docking.

Global warming is rescuing the once-rare brown Argus butterfly, scientists say.

A privately built space capsule that's zipping its way to the International Space Station has also launched something else: A new for-profit space race.

U.N. climate talks ran into gridlock Thursday as a widening rift between rich and poor countries risked undoing some advances made last year in the decades-long effort to control carbon emissions that scientists say are overheating the planet.

We are in the middle of what activists are calling an "Academic Spring," in which scientists are revolting against the companies that publish their research. The scientists say the prices being charged for subscriptions and copies of academic papers based on taxpayer-funded research are exorbitant. Thousands of scientists around the world have signed petitions and staged boycotts. The latest petition, posted on the White House's "We the People" site, has garnered more than 14,000 signatures over the past four days. 

Organic molecules — compounds that on Earth can be linked with life — encased within Martian meteorites now reveal biological activity on the Red Planet could not have formed these materials, researchers say.

A full-size replica of the space shuttle departed NASA's Florida spaceport for the agency's Texas space center early Thursday morning (May 24), riding atop an open air barge.

Global warming is rescuing the once-rare brown Argus butterfly, scientists say.

Climate researchers said Thursday the planet could warm by more than 3.5 degrees Celsius (6.3 degrees Fahrenheit), boosting the risk of drought, flood and rising seas.

Biologists on Wednesday reported they had discovered a new sensory organ on blue, humpback, minke and fin whales that helps explain why these mammals are so huge.

When NASA's space shuttle Endeavour lands at the California Science Center in Los Angeles this fall, it will be displayed in a temporary exhibit, and later a new museum facility named for an entrepreneur, explorer and philanthropist.

LONDON (Reuters) - GlaxoSmithKline said it would not proceed with its $2.6 billion offer for Human Genome Sciences unless the U.S. biotechnology company dropped a "poison pill" shareholder rights plan imposed to block the deal. Human Genome adopted the stockholder rights plan earlier this month in an attempt to ward off GSK in what is becoming an increasingly acrimonious battle between the companies that together sell new Lupus drug Benlysta. The British company is taking its $13-a-share offer direct to investors after Human Genome's board said it was inadequate. ...

LONDON (Reuters) - GlaxoSmithKline said it would not proceed with its $2.6 billion offer for Human Genome Sciences unless the U.S. biotechnology company dropped a "poison pill" shareholder rights plan imposed to block the deal. Human Genome adopted the stockholder rights plan earlier this month in an attempt to ward off GSK in what is becoming an increasingly acrimonious battle between the companies that together sell new Lupus drug Benlysta. The British company is taking its $13-a-share offer direct to investors after Human Genome's board said it was inadequate. ...

LONDON (Reuters) - Scientists have for the first time succeeded in taking skin cells from patients with heart failure and transforming them into healthy, beating heart tissue that could one day be used to treat the condition. The researchers, based in Haifa, Israel, said there were still many years of testing and refining ahead. But the results meant they might eventually be able to reprogram patients' cells to repair their own damaged hearts. ...

Science and space exploration have caught up to science fiction in many ways, producing marvels beyond the imaginings of the visionary writers of the past. Yet there are staples of science fiction that current technology is still leagues away from attaining, and which some doubt can ever be achieved.