Mercury has the shortest and fastest orbit around the Sun and experiences dramatic temperature changes as it rotates. It is a world of extremes. Explore facts about our solar system's fastest planet.

"What surprised us, at the end, was how effective this type of impact could be in explaining Mercury's unusual structure ...

Mercury ' s inner core is solid and about the same size as Earth ' s inner core, a new study using observations from NASA's MESSENGER mission has indicated. Mercury is the smallest planet in our ...