Object | Moon | Mercury |
---|---|---|
Type | Rocky satellite | Rocky planet |
Age | 4.53 billion years | 4.5 billion years |
Diameter | 3,474 km | 7,760 km |
Mean radius | 1,737 km | 3,880 km |
Mass | 7.34 × 1022 kg | 3.3 × 1023 kg |
Orbital period | 27 days | 87 days |
Surface temperature (average) |
220 K -53 °C -63 °F |
340 K 67 °C 152.6 °F |
Surface gravity | 1.6 m/s² | 3.7 m/s² |
Mean density | 3.3 g/cm3 | 5.42 g/cm3 |
Orbital distance | 384,402 km | 57 million km |
Circumference | 10,921 km | 24,378 km |
Surface area | 37 million km² | 189 million km² |
Volume | 2.19 × 1010 km3 | 2.44 × 1011 km3 |
Escape velocity | 2.3 km/s | 4.25 km/s |
Average orbital speed | 1.02 km/s | 47.36 km/s |
Semi major axis | 384 thousands km | 57 million km |
Inclination | 5.1° | 7° |
Surface pressure | 10−7 Pa | 0.5 nPa |
Atmosphere composition | argon, helium, neon |
atomic hydrogen, helium, atomic oxygen |
Crust composition | 45% silica, 19% alumina, 14% lime, 10% iron, 2% titanium dioxide, 0.6% sodium oxide |
silicate, iron sulfide |
Distance from the Milky Way center | 27,200 light years | 27,200 light years |