Slovakia's four nuclear reactors have passed so-called stress tests against potential severe accidents, earthquakes, floods and other extreme events, the country's nuclear regulator reported on Tue

Mars may have once been both cold and wet, researchers said Wednesday, suggesting a freezing Martian landscape could still have produced water needed to sustain life.

Dead pigs in China, evil factory farms in Mexico and an Al Qaeda plot involving Mexican drug cartels are a few wild theories seeking to explain a deadly swine flu outbreak that has killed up to 176 people.

Water deep below ground has safely trapped carbon dioxide for millions of years and may one day help absorb emissions of the greenhouse gas to help slow climate change, researchers said Wednesday.