Mercury
Jupiter
Diameterkm
4,879
139,820
Mass (Earth = 1)x
0.06
317.80
Surface Gravitym/s²
3.70
24.79
Mean Temperature°C
+167
-110
Distance from SunAU
0.39
5.20
Orbital Perioddays
87.97
4,331
Day Lengthhours
4222.60
9.93
Known Moons
0
95
Axial Tilt°
0.03
3.13
Orbital Velocitykm/s
47.36
13.07
Quick Facts
Mercury
- -Mercury's day-night cycle lasts 176 Earth days -- longer than its year of 88 Earth days.
- -A person weighing 68 kg on Earth would weigh only 25.7 kg on Mercury.
- -Mercury has ice in permanently shadowed craters near its poles despite surface temperatures reaching 430°C.
- -Mercury is shrinking -- its circumference has decreased by about 14 km as its core slowly cools and contracts.
Jupiter
- -Jupiter's Great Red Spot is a storm large enough to swallow Earth and has been raging for at least 350 years.
- -Jupiter has the shortest day of any planet -- it completes one rotation in just under 10 hours.
- -Jupiter's magnetic field is about 20,000 times stronger than Earth's.
- -Europa, one of Jupiter's moons, likely has more water in its subsurface ocean than all of Earth's oceans combined.