A rock collected by the Apollo 17 mission in 1972 yields a surprise.
What's the recipe for living a very long life?
Visit Alaska's boreal forest to learn its role in Earth's climate.
The Swift satellite, NASA's high-energy detector, is studying black hole mysteries.
Why can't some teens resist taking risks?
In a nebula packed with stars, not all stay with the crowd.
Mood disorders are linked to disturbances of circadian rhythms.