Researchers say that springtime snow is melting in the Arctic even faster than Arctic ice. That means less sunlight is reflected off the surface. Bare land absorbs more solar energy, which can contribute to rising temperatures on Earth. Above, a musher races along the Iditarod in the Alaskan tundra in 2007.
Former political detainees, Michael Fernandez (left), 72, and Tan Jing Quee (second from right), 66, participate in a forum in Singapore. A notebook used by Fernandez to scribble notes while he was jailed is projected behind them at the event held in 2006. Fernandez and Tan are among the hundreds of Singaporeans detained by the government without trial for, they say, political reasons.
A U.S. Navy boat is lowered to the sea from the deck of the USS Ponce in the Persian Gulf on Sept. 22. More than 30 nations are participating in an exercise responding to simulated sea-mine attacks in international waters amid rising tension with Iran.