In the back alleys of the world's capitals and the ballrooms of presidential palaces exists a black market that preys on the imagination of some and the greed of others. These black-market items are not of this world: They are moon rocks, collected decades ago by six Apollo missions and three unmanned Soviet missions to the moon.

The U.S. had two key strategic advantages over the Axis in World War II: oil and water. Although other factors played major roles in the U.S. and its allies winning the war, these two natural resources played a much larger role than recognized.

Majestic snow-capped "fourteeners," alpine meadows carpeted in wildflowers, pristine mountain lakes. These are the images most people associate with Colorado. But charming mountain terrain is not the only attraction the Centennial State has to offer the geotraveler. One of Colorado's lesser-known geologic marvels is a vast field of sand dunes - the tallest in North America - a site sure to thrill anyone.

Ask your kid what happened to the dinosaurs, and he or she will likely tell you that an asteroid killed them all. But ask how dinosaurs rose to prominence and you'll likely get a blank stare. Even many paleontologists may have little to say about the subject. But now, as EARTH explores in a feature in the February issue, new fossil discoveries are revealing the backstory of the rise of dinosaurs.

Where to next in the search for oil and gas? EARTH examines several possible new frontiers - including the Arctic, the Falkland Islands, the Levant, Trinidad and Tobago and Sudan - where oil and gas exploration are starting to take hold. One of those places, Sudan, is in the news for other reasons: South Sudan voted yesterday on whether to secede from North Sudan.

Over the past five decades, OPEC has earned a reputation for being a powerful cartel that controls the world's oil production and prices - but there are limits to OPEC's influence and wealth. In fact, many OPEC countries face grave problems, which are to some extent the result of their oil-income dependence. EARTH examines OPEC's past, current and future place in this world. Will OPEC continue to control the planet's oil for the next 50 years?

America has made great strides in recent years to reduce carbon emissions by increasing efficiency and turning to other, low or non-carbon energy sources. Meanwhile, carbon emissions in China have grown dramatically during that same time. EARTH looks at this disparity and asks the difficult questions about who is to blame when the coal China is burning is imported from "cleaner" countries and the emissions are produced to manufacture goods exported back to places with lower emissions.

In light of global concerns about emissions and climate change, the aviation industry is cleaning up its act. The industry is reducing emissions, decreasing fuel use, increasing efficiency and developing new technologies to alter its environmental impacts. The November issue of EARTH magazine focuses on the changes to learn how the aviation industry is using synthetic fuels and engineering, and even altering common flight plans to keep up with changing protocols and dwindling resources.

The American Geological Institute is pleased to announce that EARTH magazine, the magazine that explores the science behind the headlines, is now available for PC, Mac and the iPad through Zinio. Starting with the November 2010 issue, both year-long subscriptions and single copies of the online magazine can be purchased at a savings over the print edition.

Pakistan is facing tremendous water issues. This summer's flooding has left millions of people without homes and without access to clean drinking water. But water issues - both quantity and quality - are not new to this strategically important country. Waterborne diseases account for 30 percent of all deaths in Pakistan, and kill some 250,000 children each year. Per capita water availability in Pakistan is less than one-ninth of what it is in the U.S. And what's more, researchers say if Pakistan doesn't manage its water resources differently, it's going to actually run out of water. This month, EARTH magazine explores the various facets of Pakistan's water issues.