At about 4,500 years old, Stonehenge is the world’s most iconic and mysterious prehistoric ruin, and archaeologists and geologists still wrangle over the origin of some of Stonehenge's stones: Did humans transport them hundreds of kilometers to southern England? Or were glaciers responsible, acting as a kind of natural conveyor belt?

Climate change policy isn't just about science — it has to consider economics, legal and social issues. By glossing over those, researchers say, scientists are having trouble getting their message across.

No more private jets: The auto industry's Big Three seem to have gotten the message about looking poor when you're asking for a government bailout. One possibility? Carpooling.

On a foggy day in 1871, just as the Gold Rush was winding down, two grimy prospectors walked into the Bank of California, claiming to have found a trove of diamonds, rubies and sapphires. Their claim set off a new mining frenzy — but USGS surveyors suspected something wasn't quite right.

Giant retailer Wal-Mart is looking to get greener, starting with a new plan to use wind power to supply 15 percent of its energy needs.

For many tourists, Mountain Lake in southwestern Virginia has been an idyllic retreat. But in 2008, it vanished, leaving behind only cracked earth and a small pond. In this multimedia presentation, EARTH reporter Cassandra Willyard tells the geologic story behind the lake's disappearing act.

A magnitude-7.8 earthquake struck Los Angeles Thursday (sort of). During the Great Southern California ShakeOut Drill — yes, it was only a drill — millions of people, from fire and rescue workers to scientists to schoolchildren, learned what being prepared for the "Big One" entails.

Alaska's North Slope contains a vast resource of natural gas hydrates — and a significant portion of that is technically recoverable, according to a new USGS assessment. As a a result, hydrates, once considered an unconventional energy resource, may soon be a significant part of the U.S. energy mix.

With sea levels projected to rise, the tiny island nation of Maldives is in desperate straits. So its new president has announced a radical plan — to use tourist dollars to buy a new homeland.

With the world's largest natural gas reserves and the eighth-largest oil reserves, energy is critical to Russia's economy. But does Russia's aggressive posture threaten global energy supplies?

In an effort to save dwindling state dollars, prisons across the U.S. are going green, by composting waste, growing their own vegetables and recycling shoe scraps.

Don’t think you’re wasting energy? Think again, says filmmaker and one-man energy crusader Jeff Barrie. In the fervently anti-coal and pro-renewable "Kilowatt Ours," Barrie and his camera explain how flipping a light switch could destroy West Virginia mountain-tops.

With Virginia's budget in the hole for $2.5 billion, the state is planning to lay off nearly half of the geologists in its Division of Geology and Mineral Resources.

In "Heat," airing tonight on PBS' FRONTLINE, producer and reporter Martin Smith investigates climate change, from the disappearing glaciers of the Himalayas to the cement factories of India to the coal mines of the United States.

“Giant Crystal Cave,” a new National Geographic Channel documentary on exploration beneath Mexico’s Naica Mountain, follows three scientists into a harrowing cave of wonders.