What causes the shimmering, ethereal Northern Lights to suddenly brighten and dance in a spectacular burst of colorful light and rapid movement?

NASA’s fleet of THEMIS satellites reveal that explosion of magnetic energy a third of the way to the moon causes the aurora borealis.

A UK team of researchers have discovered a secondary aurora sparkling on Saturn and also started to unravel the mechanisms that drive the process.

A remote area of the Amazon river basin was once home to densely populated towns, Science journal reports.

The Upper Xingu, in west Brazil, was once thought to be virgin forest, but in fact shows traces of extensive human activity.

Researchers found evidence of a grid-like pattern of settlements connected by road networks and arranged around large central plazas.

Mayor Boris Johnson unveiled a plan on Friday to help London tackle the challenge of climate change with less carbon dioxide, more trees, better drainage and increased water efficiency.

Some 15 percent of London is deemed at high risk from flooding due to global warming — an area including 1.25 million people, 480,000 properties, 441 schools, 75 underground and rail stations, 10 hospitals and one airport.

At stake is an estimated 160 billion pounds ($293 billion) worth of assets, not just in London and its vital financial district, but all along the banks of the Thames estuary where vast new housing developments are being planned.

Important progress has been made during the latest round of United Nations-led climate change talks in Accra, Ghana, on key issues relating to a new international agreement to tackle global warming, the world body’s top official dealing with the issue said today.

The Accra meeting was the latest in a series of UN-sponsored talks in the run-up to the UN Climate Change Conference in Copenhagen in December 2009. The aim of the negotiations is to create a successor pact to the Kyoto Protocol, with first-round commitments ending in 2012, on greenhouse gas emissions reduction.

“We’re still on track, the process has speeded up and governments are becoming very serious about negotiating a result in Copenhagen,” Yvo de Boer told reporters on the final day of the week-long session.

Sumatra’s endangered elephants and tigers should get a boost from an Indonesian government move to expand one of their last havens, a four-year-old national park on the island, conservation body WWF said on Thursday.

But WWF warned that increased efforts would be vital to ensure that poaching and other illegal activities — like unsanctioned logging and settlement — did not continue in the park, Tesso Nilo in Sumatra’s Riau Province.

“This is an important milestone towards securing a future for the Sumatran elephant and tiger,” said Mubariq Ahmad, head of WWF in Indonesia as it was announced in Jakarta that the park area would be more than doubled to 86,000 hectares (212,500 acres).

Arctic sea ice shrank to its second-lowest level ever, U.S. scientists said on Wednesday, with particular melting in the Chukchi Sea, where polar bears were recently seen swimming far off the Alaskan coast.

This year’s Arctic ice melt could surpass the extraordinary 2007 record low in the coming weeks. Last year’s minimum ice level was reached on September 16, according to the National Snow and Ice Data Center.

Even if no records are broken this year, the downward trend in summer sea ice in the Arctic continues, the Colorado-based center said. Last year’s record was blamed squarely on human-spurred climate change.

A United Nations-sponsored conference that aims to tackle the environmental causes of diseases that claimed almost 2.5 million African lives each year begins in Gabon today.

In 2002 alone millions of Africans died because of unsafe water, pollution, poor sanitation, inadequate waste disposal, insufficient disease control measures and exposure to chemicals.

“African countries share common ecosystems and the impact of the environment on the health transcends national borders. Accelerated efforts are required to deal with the outbreak of diseases caused by changes in the environment,” said Regional Director of the World Health Organization (WHO) for Africa, Luis Sambo.

It’s no secret that humans are having a huge impact on the life cycles of plants and animals. UC Santa Barbara’s Steven D. Gaines and fellow researcher Dov Sax decided to test that theory by studying the world’s far-flung islands.

Their research, published this month in the Proceedings of the National Academy of Sciences, sheds surprising light on the subject of extinction rates of species on islands. The paper, “Species Invasions and Extinction: The Future of Native Biodiversity on Islands,” is one in a series of reports by this team studying how humans have altered the ecosystems of the planet.

Gaines and Sax started the project with a question: What effect are humans really having on biological diversity?