A more accurate simulation of the impact that made the Vredefort crater, Earth's largest, two billion years ago, shows the asteroid was bigger than believed.

Why the two sides of the moon are so different is one of its most enduring mysteries. Researchers now have an explanation.

Glacial runoff appears to have fed an ancient crater lake on Mars, boosting the idea that the red planet had a cold and icy past.

River delta deposits in Mars' Jezero crater formed on and off for 400,000 years—long enough to record evidence of ancient life, new research shows.