Australia on Thursday rejected a plan to let big-game hunters shoot crocodiles in the country's tropical north, saying such a scheme risked encouraging "cruel" behavior.

Under the proposal about 50 crocodile safaris a year would be allowed in the Northern Territory, where the giant reptiles have become increasingly common since they were declared a protected species in 1971.

Lights will go off in some 7,000 cities around the world for this weekend's Earth Hour event, which will aim to raise hundreds of thousands of dollars for environmental projects worldwide, organizers said Thursday.

Organizers WWF have partnered with payments giant PayPal to allow donors to contribute for specific projects in countries from Russia and India to Canada and Indonesia, using Asian fundraising site Crowdonomic.

Searchers racing to find flight MH370's "black box" face daunting hurdles ranging from undersea volcanoes to mountainous seas as they operate in one of Earth's most remote locations, experts said Wednesday.

They warned there was no guarantee that an unprecedented international search operation involving the militaries of six nations would succeed in retrieving wreckage of the doomed Malaysian Airlines plane which disappeared on March 8 with 239 people on board.

The snowpack atop mountain peaks in California and Colorado has a new set of eyes watching from high above to better gauge the amount of water that will rumble down rivers and streams each spring as runoff.

In a new mission, NASA fixed a lumbering twin-engine plane with high-tech equipment to make regular snow surveys, starting last weekend in drought-stricken California before the weather front expected to bring snow to the Sierra this week. At an altitude of up to 20,000 feet, the so-called Airborne Snow Observatory measures snowpack's depth and water content with precision.

Scientists have built Mars here on Earth -- at least within the walls of a simulation chamber that mimics conditions on the Red Planet down to its Martian dust, according to a paper out Tuesday.

The Spanish researchers built a vacuum chamber to reproduce conditions including temperature, pressure, gas composition and radiation on Mars, to help test gear designed for missions to the fourth planet from the sun.

An engine snag has delayed the arrival of a Russian spacecraft carrying three astronauts to the International Space Station until Thursday.

A rocket carrying Russians Alexander Skvortsov and Oleg Artemyev and American Steve Swanson to the International Space Station blasted off successfully early Wednesday from the Russian-leased Baikonur cosmodrome in Kazakhstan.

It was put on auction as a camera that made it to the moon and back. And it had its price — nearly $760,000.

The Hasselblad 500 sold over the weekend is described by Vienna auctioneers Galerie Westlicht as part of the equipment carried by the 1971 Apollo 15 mission, the fourth manned mission to land on the moon. Galerie Westlicht identifies the new owner as Japanese businessman Terukazu Fujisawa.

Cars drive past a traffic board reading "Warning air pollution 90 km /h recommended" near Rennes, western France on March 15, 2014

French prosecutors have opened a preliminary probe after an environmental group filed a criminal complaint over this month's spike in air pollution, a judicial source said Monday.

In its toughest move yet to eradicate illegal fishing, the European Union on Monday blacklisted Belize, Cambodia and Guinea, effectively banning their products from the world's most valuable seafood market.

The move to target the three "as countries acting insufficiently against illegal fishing" means EU states will now be required to ban their fish imports and EU vessels required to stay out of their waters.

Along with the enormous risks global warming poses for humanity are opportunities to improve public health and build a better world, scientists gathered in Yokohama for a climate change conference said Tuesday.

The hundreds of scientists from 100 countries meeting in this Japanese port city are putting finishing touches on a massive report emphasizing the gravity of the threat the changing climate poses for communities from the polar regions to the tropics.