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 early years of our solar system were a period of unimaginable chaos and violence, a gravitational free-for-all where colliding planetary embryos competed for survival. In this tumultuous ...

WASHINGTON -- Researchers have cracked a mystery at the core of Mercury -- and say there's molten fluid inside the tiny planet. They did it by using the same trick as cooks who want to know if an egg ...

WASHINGTON -- Researchers have cracked a mystery at the core of Mercury and say there's molten fluid inside the tiny planet. They did it the way a cook checks whether an egg is raw or hard-boiled.