The Bureau of Land Management says a fossil found by employees on federal land represents the earliest record of living beavers in North America.

The pair of teeth was found on BLM land in northeast Oregon.

The United States issued a ruling on Friday saying that five world populations of loggerhead sea turtles are endangered species but four are only "threatened."

The decision to split up loggerhead turtles into nine separate populations for conservation efforts was detailed in a 331-page document by the U.S. Fish and Wildlife Service and the National Oceanic and Atmospheric Administration.

In science fiction, amber preserved the DNA that allowed rebirth of dinosaurs in Jurassic Park. In real life, amber preserved feathers that provide a new image of what dinosaurs looked like.

"Now, instead of scaly animals portrayed as usually drab creatures, we have solid evidence for a fluffy colored past," reports Mark A. Norell of the American Museum of Natural History in New York.

Scientists tracking a rare western Pacific gray whale were shocked last winter when the endangered animal left the Asian coast, crossed the Bering Sea and swam south along Alaska, British Columbia and the Pacific Northwest coasts.

Researchers are back in Russia to see whether the feat will be repeated by other Pacific gray whales.

The area covered by Arctic sea ice reached its lowest point this week since the start of satellite observations in 1972, German researchers announced on Saturday.

"On September 8, the extent of the Arctic sea ice was 4.240 million square kilometers (1.637 million square miles). This is a new historic minimum," said Georg Heygster, head of the Physical Analysis of Remote Sensing Images unit at the University of Bremen's Institute of Environmental Physics.

A dead NASA satellite will soon fall to Earth, but the space agency says there is very little chance that a piece of it will hit someone.

NASA says the 20-year-old satellite will probably fall sometime between late September and October. Pieces of it could land anywhere in the six inhabited continents in a worldwide swath from south of Juneau, Alaska, to just north of the tip of South America. NASA scientists estimate a 1-in-3,200 chance a satellite part could hit someone. Most of it will burn up after entering Earth's atmosphere.

Were it not for meteorites striking Earth some four billion years ago, humans would never have laid eyes on the gold that has raised and ruined civilizations, according to a study published Thursday.

Two hundred million years earlier, during the violent throes of planetary formation, Earth was a mass of molten minerals set afire by collisions with planet-sized heavenly bodies.

It's more than 40 years since Neil Armstrong became the first man to walk on the Moon, but his memories of the historic flight remain as undimmed as his passion for further exploration of space.

The Apollo 11 commander, now aged 81, relived the 1969 mission that enthralled the world as he watched Google's new high-definition images of the Moon in Australia last week.

Space junk has made such a mess of Earth's orbit that experts say we may need to finally think about cleaning it up.

That may mean vacuuming up debris with weird space technology — cosmic versions of nets, magnets and giant umbrellas, according to the chairman of an expert panel that issued a new report on the problem Thursday.

A 3.6-million-year-old woolly rhinoceros fossil discovered in Tibet indicates that some giant mammoths, sloths and saber-tooth cats may have evolved in highlands before the Ice Age, experts say.

Paleontologists from the Natural History Museum of Los Angeles County and the Chinese Academy of Sciences, who found the rhino's complete skull and lower jaw in 2007, argue that it adapted to the global cooling before it happened.