Mercury

space · planets · rocky world

Tiniest planet. Mercury is the smallest planet in the Solar System and the closest one to the Sun.

Moon's twin. Its surface looks a lot like Earth's Moon, covered in craters and bright streaks called ray systems.

Giant crater. Its biggest crater, Caloris Planitia, is about 1,550 km wide, roughly one-third the size of the whole planet!

Morning or evening star. Because it stays close to the Sun in our sky, Mercury appears as a 'morning star' or 'evening star.'

Rocky and thin-aired. Mercury is a rocky planet with only a trace of atmosphere and gravity a bit stronger than Mars.