Eight worlds, one star
Select a planet to open its profile. Sizes are drawn to scale against Earth, so you can see just how much of the solar system's bulk Jupiter holds.
Planet 3 · Terrestrial
Earth
Equatorial diameter 12,742 km
Earth
Earth
1×Earth's diameter
Sizes shown next to Earth are scaled from published equatorial diameters (NASA planetary fact sheets). Distances are average distances from the Sun.
- Distance from Sun
- 149.6 million km (1 AU)
- Orbital period
- 365.25 days
- Rotation
- 23 hours 56 minutes
- Moons
- 1 — the Moon
- Atmosphere
- 78% nitrogen, 21% oxygen, 0.9% argon, plus carbon dioxide and water vapour
- Composition
- Rocky world with a liquid iron–nickel outer core generating a magnetic field; oceans cover about 71% of the surface
- Temperature
- Average about 15 °C
Why it matters
- Earth is the only world where liquid water is known to be stable on the surface, and the only one with known life.
- Its magnetic field deflects the solar wind, producing auroras near the poles.
- Plate tectonics continuously recycle the crust — a process not confirmed on any other planet.