How do tsunami warning systems work? How quickly could one be built in the Indian Ocean?

Cassini finds lightning strikes on Saturn, haze on moon Titan, dust between the rings, and new rotation rate.

New view of crystals that form into planets in protoplanetary disks. Which came first, the planet or the crystals?

How do we forecast or predict volcanoes? How do volcanoes change the landscape? How does life return after an eruption?

Amateur astronomers watch variable stars, asteroids, comets — helping create a better picture of the universe.

Evidence from ice cores in Greenland and Antarctica show how fast the climate has changed in the past. In this era of global warming, you can’t count on a slow, gradual, predictable warming.

Why don’t the rings of Saturn just disappear over millions of years. It’s the recycling, that’s why!

Lunar eclipses are fleeting events, but their history goes deep. And what’s what with that reddish hue?

Tornadoes kill 60 Americans each year. How do we predict tornadoes? How do we make houses safer? Where do tornadoes get their energy?

Chandra links gamma-ray bursts to supernovas. What really causes these gigantic explosions?