Earth

Did You Know?
Earth is the third planet from the Sun and largest of the terrestrial planets. Surprisingly, while it is only the fifth largest planet in terms of size and mass, it is the densest (5,513 kg/m3) of all the planets. Earth is the only planet in the solar system not named after a mythological being. Instead, its name is derived from the Old English word "ertha" and the Anglo-Saxon word "erda" which means ground or soil. Earth is currently the only known planet to support life - and lots of it.

Planet Profile
Mass (kg) 5.98 x 1024
Diameter (km) 12756
Mean density (kg/m3) 5520
Escape velocity (m/s) 11200
Average distance from Sun 1 AU (149,597,890 km)
Rotation period (length of day in Earth days) 1 (23.93 hours)
Revolution period (length of year in Earth days) 365.26
Obliquity (tilt of axis degrees) 23.4
Orbit inclination (degrees) 0
Mean surface temperature (K) 281
Mean maximum surface temperature (K) 310
Mean minimum surface temperature (K) 260
Highest point on surface Mount Everest (over 8 km above sea-level)
Atmospheric components
  • 78% nitrogen,
  • 21% oxygen,
  • 1% argon
Surface Materials basaltic and granitic rock and altered materials