PLANET EARTH:Word origin: eorthe (from Old English) meaning "ground, soil, dry land"
Other terms: Globe, World
Situated in: Milky Way galaxy
Position: 3rd planet from the Sun
Size: 5th largest planet in the Solar system
Shape: Oblate Spheroid
Age: 4.54 billion years (according to geologists and geophysicists)
Population: 6.8 billion (as of 2009)
Rotation: 86,400 seconds or 24 hours (relative to the Sun, mean solar day) (15 degrees/hr)
Orbit: 150 million km every 365.2564 mean solar days
Average orbital speed: 29.783 km/s (107,218 km/h)
Eccentricity: 0.016710219
Mean radius: 6371 km (3959 mi)
Mean diameter: 12,742 km (7919 mi)
Mean Circumference: 40041 km (24886 mi)
Surface area: 510,072,000 sq. km
148,940,000 km² land (29.2 %)
361,132,000 km² water (70.8 %)
Volume: 1.0832073 e12 cu. km
Mass: 5.9736 e24 kg
Mean density: 5.5153 g/cc
Equatorial surface gravity: 9.780327 m/s² (0.99732 g)
Escape velocity: 11.186 km/s
Equatorial rotation velocity: 1,674.4 km/h (465.1 m/s)
Axial tilt: 23.439281 degrees
Surface temperature:
min mean max
184 K 287 K 331 K
-89 °C 14 °C 57.7 °C
Climate: tropical, subtropical, temperate, and polar
Seasons: summer, autumn, winter, spring
Surface pressure of atmosphere: 101.3 kPa (14.7 psi)
Composition of atmosphere:
78.08% Nitrogen (N2)
20.95% Oxygen (O2)
0.93% Argon
0.038% Carbon dioxide
About 1% water vapor
Earth-moon distance: 384,320 km (238,857 mi)
Earth-sun distance: 150 million km (93 million mi)
