Meteorite specialist Dr. Denton Ebel talks asteroids bigger than Everest, glass mini-marbles raining from the sky, and dinosaur toast.

In 1669, the fastest and largest lava flow documented for Mount Etna on the island of Sicily killed most of Catania's 20,000 residents and destroyed much of the city. Why are scientists now watching Etna more than any other volcano in Europe? Find out.

During a July 2004 project to drill an ice core from the top of Peru's Andes Mountain, the lead researcher took a detour… and made a discovery with profound implications. Learn more.

By analyzing the relics glaciers hold — compacted snow and trapped air from ancient atmospheres, ash from long-quiet volcanoes, dust, insects, and pollen — scientists can reconstruct hundreds of thousands of years of Earth’s climate.

In the past two million years alone, Earth has experienced around 20 ice ages — cycles of advance and retreat of large continental ice sheets. When is the next one due? And will global warming change that due date?

Climate change isn’t always slow, small, and imperceptible in a human lifetime. Ice core analysis has found a single decade in which temperatures over Greenland shot up about 15 degrees Celsius.

The Sloan Telescope has a digital camera the size of a dishwasher that’s sophisticated enough to capture every luminous object in the northern celestial hemisphere. Take a closer look.

Scientists know that the unusual and rapid temperature jump of the Younger Dryas was felt over half the globe. But they're only now beginning to understand why.

Have you ever stumbled upon a discovery while looking for something completely different? See what surprises astronomers found as part of the Sloan Digital Sky Survey.

What is the Universe’s arrangement today? What did it look like at its birth? And how did we get from then to now? These are just some of the “Big Questions” astronomers are making headway answering.