Science & Engineering

Earth Constants

Physical and orbital constants of Earth — radius, mass, gravity, magnetic field, atmosphere.

Size and mass

Equatorial radius6 378.137 km
Polar radius6 356.752 km
Mean radius6 371.0 km
Circumference (equator)40 075 km
Surface area5.10 × 10⁸ km²
Volume1.083 × 10¹² km³
Mass5.972 × 10²⁴ kg
Mean density5.514 g/cm³

Gravity and motion

Standard gravity g9.806 65 m/s²
Escape velocity11.186 km/s
Axial tilt23.4393°
Rotation period (sidereal)23 h 56 min 4.1 s
Day (mean solar)86 400 s
Orbital period365.256 days
Orbital speed29.78 km/s
Mean distance from Sun (AU)1.000 AU = 1.496 × 10⁸ km

Atmosphere and magnetic field

Atmosphere composition78.08% N₂, 20.95% O₂, 0.93% Ar, ~0.04% CO₂
Mean surface pressure101.325 kPa
Atmospheric scale height~8.5 km
Magnetic field (surface)25–65 μT
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