Scientists unveiled a new method on Wednesday for extracting metallic iron from its ore while curbing Earth-warming carbon dioxide emissions.

This is achieved with electrolysis and has the added benefit of releasing oxygen as a byproduct, a team from the Massachusetts Institute of Technology reported in the journal Nature.

For three quarters of an hour a giant swarm of locusts streams across the sky above southwest Madagascar.

Along National Route Seven, normally an artery for tourists enjoying breathtaking views of the island's vast open spaces, a 15 kilometre long (nine mile) swarm clouds the sky.

Landing astronauts safely on Mars is one of the biggest technological hurdles for any future manned mission to the Red Planet, even more complicated than last year's daring rover touchdown.

NASA dazzled observers by landing the one-ton Curiosity rover on Mars in August in a high-speed operation using a sky crane and supersonic parachute, but experts say the task would be even more challenging with humans onboard.

A community group that raised $1.3 million in a six-week online fundraising effort has purchased a laboratory once used by visionary scientist Nikola Tesla.

"We're feeling very excited and gratified that we've reached this milestone," said Jane Alcorn, president of the Tesla Science Center at Wardenclyffe, on New York's Long Island. Her group announced last week that it had finalized the purchase of the Tesla lab and property for $850,000.

The old coastal road in this fishing village at the eastern edge of Grenada sits under a couple of feet of murky saltwater, which regularly surges past a hastily-erected breakwater of truck tires and bundles of driftwood intended to hold back the Atlantic Ocean.

For Desmond Augustin and other fishermen living along the shorelines of the southern Caribbean island, there's nothing theoretical about the threat of rising sea levels.

Scientists say a disease destroying entire crops of cassava has spread out of East Africa into the heart of the continent, is attacking plants as far south as Angola and now threatens to move west into Nigeria, the world's biggest producer of the potato-like root that helps feed 500 million Africans.

"The extremely devastating results are already dramatic today but could be catastrophic tomorrow" if nothing is done to halt the Cassava Brown Streak Disease, or CBSD, scientist Claude Fauquet, co-founder of the Global Cassava Partnership for the 21st Century, told The Associated Press.

Brazilian geologists on Monday announced the discovery, 1,500 kilometers (900 miles) from Rio, of what could be part of the continent submerged when the Atlantic Ocean was formed as Africa and South America drifted apart 100 million years ago.

Roberto Ventura Santos, a top official at Brazil's Geology Service (CPRM), said granite samples were found two years ago during dredging operations in an area known as "Rio Grande Elevation", a mountain range in Brazilian and international waters.

Any day now, billions of cicadas with bulging red eyes will crawl out of the earth after 17 years underground and overrun the East Coast. The insects will arrive in such numbers that people in the southern state of North Carolina to Connecticut in the northeast will be outnumbered roughly 600-to-1. Maybe more.

Scientists even have a horror-movie name for the infestation: Brood II. But as ominous as that sounds, the insects are harmless. They won't hurt you or other animals. At worst, they might damage a few saplings or young shrubs. Mostly they will blanket certain pockets of the region, though lots of people won't ever see them.

Europe's lightweight rocket, Vega, was launched from Kourou space base in French Guiana late Monday for the first mission, webcast live, since its maiden flight in February last year.

The rocket lifted off at 0206 GMT Tuesday, carrying two small Earth-observation satellites and a micro-satellite.

Gigantic animals which once roamed Australia were mostly extinct by the time humans arrived, according to a new study Tuesday which suggests climate change played the key role in their demise.

For decades, debate has centered on what wiped out megafauna such as the rhinoceros-sized, wombat-like Diprotodon, the largest known lizard, and kangaroos so big that scientists are studying whether they could hop.