Terrestrial planet
Mercury
The smallest planet and the one closest to the Sun, Mercury is a cratered world with extreme temperature swings between its sunlit and night sides.
- Avg. distance
- 0.39 AU
- Diameter
- 4,879 km
- Day length
- ~59 Earth days (sidereal)
- Year length
- ~88 Earth days
- Moons
- 0
Did you know?
Despite being innermost, ice can persist in permanently shadowed polar craters.