A half mile (800 meters) below the ground at Prudhoe Bay, above the vast oil field that helped trigger construction of the trans-Alaska pipeline, a drill rig has tapped what might one day be the next big energy source.

The U.S. Department of Energy and industry partners over two winters drilled into a reservoir of methane hydrate, which looks like ice but burns like a candle if a match warms its molecules. There is little need now for methane, the main ingredient of natural gas. With the boom in production from hydraulic fracturing, the United States is awash in natural gas for the near future and is considering exporting it, but the DOE wants to be ready with methane if there's a need.

A build-up of carbon dioxide in the upper levels of Earth's atmosphere risks causing a faster accumulation of man-made space junk and resulting in more collisions, scientists said on Sunday.

While it causes warming on Earth, CO2 conversely cools down the atmosphere and contracts its outermost layer, the thermosphere, where many satellites including the International Space Station (ISS) operate, said a study published in the journal Nature Geoscience.

Tens of thousands of people were flocking to Australia's tropical north Monday to watch a rare total solar eclipse, a phenomenon officials say has not been seen in the region in 1,300 years.

The Queensland state government expects up to 60,000 visitors will witness on Wednesday the alignment of the sun, moon and earth which creates one of the most spectacular sights in nature, essentially turning day into night.

A newly-discovered alien planet seven times bigger than Earth may be able to support life, astronomers wrote in a study appearing in the journal "Astronomy and Astrophysics."

The planet, dubbed HD 40307g, is one of only a few to be discovered in the "habitable zone": a sweet spot, neither too close or too far from its sun, where liquid water could exist.

An American regarded as a father of computer graphics, an Indian literary critic and a Japanese molecular cell biologist have received the Kyoto Prize, Japan's highest private award for global achievement.

The Inamori Foundation awarded its advanced technology prize on Saturday to U.S. computer scientist Ivan Sutherland, who developed the graphic interface program Sketchpad in 1963.

Scientists said Wednesday they have developed a method to "see through" layers of thin, solid material in a breakthrough that holds promise for medical imaging, nanotechnology -- and the spy trade.

Still in its infancy, the technique using laser and computer decoding has allowed a team from the Netherlands and Italy to "see" an object behind a non-see-through barrier made of ground glass.

New Zealand's government said Friday that it would not sign on for a second stage of the Kyoto Protocol climate treaty, a stance that angered environmentalists and political opponents.

The announcement came the same day that Australia said it would stay the course and commit to "Kyoto 2."

Fishing nations meet in Morocco next week to thrash out tuna quotas as experts urge maintaining bluefin catch limits amid promising signs of the decimated species making a comeback.

Hunted to the brink of extinction to feed a burgeoning sushi market, the Atlantic bluefin tuna was placed on the endangered list of the International Union for the Conservation of Nature (IUCN).

Affordable fuel from grasses, trees and plant waste that packs enough of a punch to power a plane? Scientists said Wednesday this can be done using chemistry to boost basic fermentation processes.

A team at the University of California in Berkeley said it had developed a method to add carbon atoms to biofuels obtained from fermentation -- currently not potent enough to replace gasoline, jet fuel or diesel.

Paleontologists said Wednesday they have found small blades in a South African cave proving that Man was an advanced thinker making stone tools 71,000 years ago -- millennia earlier than thought.

The find suggests early humans from Africa had a capacity for complex thought and weapons production that gave them a distinct evolutionary advantage over Neanderthals, say the authors of a study published in Nature.