A startup evidently devoted to mining asteroids for metals is to make its public debut Tuesday in the U.S. northwest city of Seattle, seeking to redefine the term "natural resources."

X Prize founder Peter Diamandis and a former NASA astronaut are slated to unveil Planetary Resources, which boasts an impressive list of backers including Google co-founder Larry Page and famed film maker James Cameron.

Four new species of freshwater crab, bright purple in color, have been discovered in the biologically diverse Philippines, according to a scientific paper.

The tiny crustaceans were found in streams in remote areas of the Palawan island group, according to a team led by Hendrik Freitag, of Germany's Senckenberg Museum of Zoology.

Kenyan rangers shot dead five suspected elephant poachers in a night-time firefight in the north of the country, the Kenya Wildlife Service (KWS) said on Saturday.

"Five suspected poachers were last night gunned down and one escaped during a fierce exchange of fire with Kenya Wildlife Service rangers at Chepareria in West Pokot County," it said.

Polar bears diverged from their closest relatives 600,000 years ago, far earlier than previously thought, suggesting more challenges in the face of climate change, scientists said Thursday.

Previous genetic analysis of polar bears had determined the species was only about 150,000 years old. But in fact, it took them five times longer for the polar bear to adapt to arctic conditions, according to the study by Frank Hailer and colleagues.

The acceleration of climate change is stressing mountain plants in Europe and driving them to migrate to higher altitudes, according to a study released Thursday by U.S. researchers.

The plant migration is also decreasing species diversity, the study's authors said in the April 20 edition of the journal Science.

Seismologists say last week's powerful earthquake off western Indonesia increased pressure on the source of the devastating 2004 tsunami: a fault that could unleash another monster wave sometime in the next few decades.

"The spring was pushed a little bit tighter," said Kerry Sieh, director of the Earth Observatory of Singapore.

China says 16 endangered finless porpoise have been found dead since the beginning of the year, due in part to what experts suspect is water pollution and climate change, state media reported.

The freshwater porpoise -- which is known in Chinese as the "river pig" -- mainly lives in China's Yangtze River and two lakes linked to the waterway, and the deaths have raised concern the rare animal is headed for extinction.

Discovery on Thursday will become the first spaceship of the retired U.S. shuttle fleet to enter its permanent home as a museum artifact, marking a solemn end to the 30-year U.S. space flight program.

A team of about 20 veteran astronauts who flew to space aboard Discovery will surround the celebrated spacecraft and escort it to a branch of the Smithsonian National Air and Space Museum outside the U.S. capital.

A University of California San Diego scientist was able to use his math and physics knowledge to argue his way out of a $400 traffic ticket.

In a paper titled "The Proof of Innocence," senior research scientist Dmitri Krioukov successfully appealed his failure-to-stop ticket by explaining that he may have appeared to an officer that he didn't stop when he actually did, according to the Los Angeles Times .

The fact that land-bound dinosaurs laid eggs is what sealed their fate of mass extinction millions of years ago while live birthing mammals went on to thrive, scientists said Wednesday.

In a new explanation for mammals' evolutionary victory over dinosaurs, researchers said a mathematical model has shown that infant size was the clincher.