The rock found in Morocco was even weirder than it looked. The olive green chunk, speckled with white and brown, has chemical and physical properties similar to the planet Mercury. But some experts doubt that the 4.56-billion-year-old meteorite is from the planet closest to our sun.

Building huge turbine farms too close together might significantly reduce their power, some atmospheric scientists say. The problem is “wind shadow” — the turbulence created by one big cluster of turbines that steals wind from another cluster down the road.

Some Colorado doctors who’ve treated victims of recent mass shootings and everyday gun violence say they’re deeply disturbed by and opposed to guns. But other doctors don’t support the new gun restrictions lawmakers are talking about in Denver and Washington, D.C.

What if a gun could only be fired by its rightful owner? What if it recognized a grip or fingerprint, or communicated with a special ring? It’s been a fantasy for years, and in the wake of the Sandy Hook tragedy, so-called smart gun technology is back in the spotlight.

U.S. and other NATO troops are spending less time fighting the Taliban and more time making local Afghan governments self-sufficient. It’s a slow process.

Early March is when Yosemite National Park officials would normally be gearing up for the busy tourist season. Instead, they’re figuring out how to cut $1.5 million from their budget because of the recent sequestration that forced across-the-board cuts. The National Park Service must now cut $134 million from sites around the country.

Federal health officials warned that a dangerous group of superbugs has become increasingly common in hospitals throughout the past decade. The Centers for Disease Control and Prevention says the bacteria are resistant to virtually all antibiotics, including the ones doctors use as a last-ditch option.

U.S. Army Spc. Tyler Jeffries lost both legs in a roadside bombing last October in Afghanistan, and he has been learning to walk on prosthetic legs. But Jeffries was determined to meet his buddies when they returned from duty in January.