Earth

Earth, our home planet

Earth, our home planet, is the third planet from the Sun and also the fifth largest in our solar system. It is the only known planet that supports life. Earth's diameter is just a few hundred kilometers larger than that of Venus. The four seasons are a result of Earth's axis of rotation being tilted more than 23 degrees.

Nearly 70 percent of the Earth's surface is covered by Oceans of at least 4 km deep. Our atmosphere consists of 78 percent nitrogen, 21 percent oxygen and traces of argon, carbon dioxide and water. Water vapor in the atmosphere is responsible for much of Earth's weather. The atmosphere affects long-term climate as well as daily weather; shields us from harmful radiation coming from the Sun; and protects us from meteors which burn up before they can hit the surface.

Earth has only one natural satellite - the moon. The interaction of the Earth and the Moon slows the Earth's rotation by about 2 milliseconds per century. Current research indicates that about 900 million years ago there were 481 18-hour days in a year.

Earth: Facts & Figures

  • Average Distance from the Sun: 149,597,890 km
  • Perihelion (closest): 147,100,000 km
  • Aphelion (farthest): 152,100,000 km
  • Equatorial Radius: 6,378.14 km
  • Equatorial Circumference: 40,075 km
  • Volume: 1,083,200,000,000 km3
  • Mass: 5,973,700,000,000,000,000,000,000 kg
  • Density: 5.515 g/cm3
  • Surface Area: 510,065,700 km2
  • Equatorial Surface Gravity: 9.766 m/s2
  • Escape Velocity: 40,248 km/h
  • Length of Day: 23.934 hours
  • Length of Year: 365.24 Earth days
  • Mean Orbit Velocity: 107,229 km/h
  • Orbital Eccentricity: 0.01671022
  • Orbital Inclination to Ecliptic: 0.00005 degrees
  • Equatorial Inclination to Orbit: 23.45 degrees
  • Orbital Circumference: 924,375,700 km
  • Minimum/Maximum Surface Temperature: -88/58 °C
  • Atmospheric Constituents: Nitrogen, Oxygen
  • Number of moons: 1

Source: NASA