California's gold rush may long be over, but mercury-contaminated soil from mining activities in the foothills of the Sierra Nevada continues to flow downstream, impacting fish and the environment, a new study suggests.

The heavy metal tends to be loosened during major floods that occur about once a decade and likely will continue unless something is done to prevent mercury-laden sediment from eroding and ending up in the state's agricultural heartland, according to the study published online Monday in the Proceedings of the National Academy of Sciences.

Ever wonder why snakes inspire such fear? A new study on monkeys out Monday says the brain has specific cells that fire off rapid warnings when confronted with slithery danger.

Certain neurons respond "selectively" to images of snakes, and they outpace comparable neurons that react to visuals of faces, hands or geometric shapes, the researchers said.

NASA said Monday it is on track to launch its Maven probe to Mars next month to find out why the Red Planet lost much of its atmosphere.

The unmanned spaceship is scheduled to leave Earth on November 18 at 1:38 pm (1739 GMT).

Meteorologists may have found a way to predict some killer heat waves up to three weeks in advance. Now, the best they can do is about 10 days.

An earlier warning would help cities prepare for the heat wave, arrange to open up cooling centers and check on the elderly, said Gerald Meehl, co-author of a study that describes the forecasting clue.

An expedition to a remote part of northern Australia has uncovered three new vertebrate species isolated for millions of years, with scientists Monday calling the area a "lost world".

Conrad Hoskin from James Cook University and a National Geographic film crew were dropped by helicopter onto the rugged Cape Melville mountain range on Cape York Peninsula earlier this year and were amazed at what they found.

Europe's heaviest-ever cargo carrier to the International Space Station undocked on Monday after completing its mission, and will burn up in Earth's atmosphere on Saturday, the NASA space agency said.

Filled with about six tonnes of garbage and waste produced on board the ISS, the Automated Transfer Vehicle (ATV) separated from the ISS at 0855 GMT, when it was orbiting at about 420 kilometers (260 miles) over Kazakhstan, said a NASA statement.

A Texas hunting club said Friday it aims to raise up to a million dollars for endangered black rhinoceroses by auctioning off a permit to kill one in Namibia.

"First and foremost, this is about saving the black rhino," said Ben Carter, executive director of the Dallas Safari Club, which is hosting the auction early next year.

A Greenpeace activist Saturday staged a two-hour protest in a tent suspended from the second floor of the Eiffel Tower against Russia's detention of 30 members of the environmental lobby group.

The activist also unveiled a banner with the slogans "Free the Arctic 30" and "Militants in prison, climate in danger", forcing authorities to close the French monument to tourists in the morning.

Former U.S. vice president Al Gore on Thursday urged President Barack Obama to block the Keystone XL oil pipeline from Canada, likening the carbon-intense project to drug addiction.

Gore, who has championed action against climate change since his razor-thin loss for the White House in 2000, praised Obama's general views on climate change but said his fellow Democrat faced a key test on the proposed project.

Scientists in China said Thursday they had designed a "smart" window that can both save and generate energy, and may ultimately reduce heating and cooling costs for buildings.

While allowing us to feel close to the outside world, windows cause heat to escape from buildings in winter and let the Sun's unwanted rays enter in summer.