Earth

Steven Dutch, Natural and Applied Sciences, University of Wisconsin - Green Bay First-time Visitors: Please visit Site Map and Disclaimer. Use "Back" to return here.

Earth: Vital Statistics

Average distance from Sun 93,000,000 miles
Closest to Sun (perihelion) 91,500,000 miles about Jan. 3
Farthest from Sun (aphelion) 94,500,000 miles about July 4
Rotates on axis in 24 hrs., revolves around Sun in 365.2564 days.
Diameter: through equator 7928 miles; through poles 7899 miles
Difference is due to centrifugal force of earth's rotation (at equator, centrifugal force is about 3/1000 as much as Earth's gravity)
Surface area: 198,000,000 square miles, of which about 50,000,000 is land.
Mass: 6x10²⁷ grams or 6,000,000,000,000,000,000,000 (6x10²¹) metric tons
Of the Earth's mass:
- about 1/3 is in the core
- 2/3 in the mantle
- 4/1000 in the crust
- 2/10,000 in the oceans
- 1/1,000,000 in the atmosphere
- 1/100,000 in ice caps

Life (based on carbon--over 3 million species)
Atmosphere (79% nitrogen, 20% oxygen, 1% argon, variable amounts of water vapor, carbon dioxide)
Presence of Large Amounts of Liquid Water
Very Active Geologically
- Active erosion by water
- Plate tectonics--metamorphism, deformation, granitic rocks
- Few impact craters visible
Strong Magnetic Field for Such a Small Planet
Has an Unusually Large Satellite in Proportion to Its Size

Raymond Siever, 1975, The Earth. Scientific American, vol. 233, no. 3, pp. 82-91
Raymond Siever, 1983, The Dynamic Earth. Scientific American, vol. 249, no. 3, pp. 46-55
Kasting, James F.; Toon, Owen B.; Pollack, James B., How climate evolved on the terrestrial planets Scientific American, v.258 p90-7 February 1988

Created 20 May 1997, Last Update 2 Jun 1997

Not an official UW Green Bay site