Mercury doesn't give up its secrets easily. The smallest planet in our solar system is also one of the most extreme—a sun-scorched, metal-rich world with a puzzling magnetic field and lavas unlike ...

The main working hypothesis for the Mercury problem says that the planet is the victim of a collision with a different-sized object. The cataclysmic collision stripped much of the planet's mantle and ...

Aluminum looks strong and solid until mercury touches it. This reaction shows how fragile the metal becomes in seconds.