Solar System

Earth

Terrestrial planet · Our home world · The only known world with life

The only place known to host life, Earth sits in the Sun's habitable zone with liquid water, a protective atmosphere, and a single large Moon.

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Texture: Solar System Scope (CC BY 4.0)

Key facts

Distance from Sun 1.00AU 149.6 million km
Radius 6,371km 1× (reference)
Mean temperature 15°C −88 to 58 °C

Time & motion

A day (one spin) 23.9 hours The reference day for every comparison here.
A year (one orbit) 365.2 days This is the reference year for the whole system.
Surface gravity vs Earth
9.8 m/s² 1 g (reference)
0Earth = 1 g2.5×

Mass & physical characteristics

Mass 5.97 × 10²⁴kg 1× (reference)
Density 5.51g/cm³ Water = 1.0 g/cm³
Escape velocity 11.2km/s Speed to break free
Orbital velocity 29.8km/s Speed around the Sun
Axial tilt 23.4° This tilt is what gives Earth its seasons.

Atmosphere & magnetosphere

Atmosphere

78% nitrogen, 21% oxygen, 0.9% argon, ~0.04% carbon dioxide. The only known atmosphere rich in free oxygen — made by living things.

Surface pressure 1 bar (reference) Relative to Earth's 1 bar

Magnetic field

A strong dipole field that shields the surface from the solar wind.

Moons & rings

Known moons 1 One moon — the Moon.
Notable moons
The Moon

Make-up

Composition

Nitrogen–oxygen atmosphere, liquid-water oceans, active plate tectonics.

Notable features

  • The Mariana Trench (~11 km deep) and Mount Everest (~8.8 km tall) mark its extremes.

Fun facts

  • Earth is the densest planet in the Solar System and the only one not named after a god.
  • It is the only known world with liquid water on its surface — and with life.
  • Its molten-iron core generates a magnetic field that shields us from the solar wind.
  • The Moon drifts away from Earth by about 3.8 cm every year.
  • Earth's oxygen-rich air is produced by photosynthetic life over billions of years.

Exploration

Apollo 11–17 1969–72 Carried twelve astronauts to the Moon.
International Space Station 1998– A continuously crewed orbital laboratory.
Landsat 1972– Half a century of continuous Earth observation.