A wobbling of the Earth on its axis about 20,000 years ago may have kicked off a beginning to the end of the last ice age. Glaciers in the Arctic and Greenland began to melt, which resulted in a warming of the Earth, a new study says. Above, Greenland's Russell Glacier, seen in 1990.
The last big ice age ended about 11,000 years ago, and not a moment too soon — it made a lot more of the world livable, at least for humans.
But exactly what caused the big thaw isn't clear, and new research suggests that a wobble in the Earth kicked off a complicated process that changed the whole planet.
Ice tells the history of the Earth's climate: Air bubbles in ice reveal what the atmosphere was like and what the temperature was. And scientists can read this ice, even if it's been buried for thousands of years.
Six-term Republican Sen. Richard Lugar of Indiana is facing his first primary challenge since winning the job in the 1970s. The race is attracting big money from outside groups and superPACs, and is seen as a test of the strength of the Tea Party movement versus the power of incumbency.
Selina Gray of Sanford, Fla., shows her sign at a rally protesting the death of Trayvon Martin, the unarmed teen shot by a neighborhood watch volunteer. Authorities have cited the state's "stand your ground" law as a reason charges have not been filed in Martin's death.
Two of America's best-known companies, Coca-Cola and PepsiCo, have dropped their memberships in the American Legislative Exchange Council, a low-profile conservative organization behind the national proliferation of "stand your ground" gun laws.
On Thursday night, ABC's Scandal will step out as a rarity on TV: a show developed by one of the most powerful black women in TV, Grey's Anatomy creator Shonda Rimes, depicting a powerful black woman in Washington, D.C.: Olivia Pope, a top-flight crisis manager.
She's a "fixer" so impressive, she can negotiate down payments with the Ukrainian mob in a burst of rapid-fire dialogue. She is played by Kerry Washington, whom you might recognize from wife and girlfriend roles in films like The Fantastic Four and Ray.