What is Earth?

Overview

Earth, our home planet, is the third planet from the Sun and the only known world to support life. It's a rocky, terrestrial planet with a dynamic surface shaped by water, wind, and tectonic activity.

  • Diameter: 12,742 km
  • Distance from Sun: 150 million km
  • Mass: 5.97 x 10²⁴ kg
  • Orbit Period: 365.25 days
  • Rotation Period: 23.93 hours
A sky view of Earth from Suomi NPP

Image credit: NASA/NOAA (Suomi NPP)

Details

Atmosphere: Earth's atmosphere is rich in nitrogen (78%) and oxygen (21%), with trace amounts of other gases. It protects life by filtering solar radiation and maintaining temperature.

Moons: Earth has one natural moon, often simply called "the Moon," which influences tides and stabilizes the planet's axial tilt.

Surface: About 71% of Earth's surface is covered by water, with vast oceans and continents featuring mountains, volcanoes, and plains.

Exploration: Humans have explored Earth extensively, with space missions like Apollo providing views from above. Satellites continue to monitor its climate and geology.

Fun Fact: Earth's magnetic field, generated by its molten iron core, shields us from solar wind and cosmic radiation.