Mercury

Did You Know?
Mercury is the closest planet to the Sun and due to its proximity it is not easily seen except during twilight. For every two orbits of the Sun, Mercury completes three rotations about its axis and up until 1965 it was thought that the same side of Mercury constantly faced the Sun. Thirteen times a century Mercury can be observed from the Earth passing across the face of the Sun in an event called a transit, the next will occur on the 9th May 2016.

Planet Profile
Mass (kg) 3.3 x 1023
Diameter (km) 4879.4
Escape velocity (m/s) 4300
Average distance from Sun 0.387 AU (57,909,175 km)
Rotation period (length of day in Earth days) 58.65
Revolution period (length of year in Earth days) 87.97
Obliquity (tilt of axis degrees) 0
Orbit inclination (degrees) 7
Mean surface temperature (K) 452
Maximum surface temperature (K) 700
Minimum surface temperature (K) 100
Largest known surface feature Caloris Basin (1350 km diameter)
Atmospheric components trace amounts of hydrogen and helium
Surface materials basaltic and anorthositic rocks and regolith