Earth: Facts & Figures

A true-color NASA satellite mosaic of Earth.

Earth is an ocean planet. Our home world's abundance of water -- and life -- makes it unique in our solar system. Other planets, plus a few moons, have ice, atmospheres, seasons and even weather, but only on Earth does the whole complicated mix come together in a way that encourages life -- and lots of it.

Discovered By Known by the Ancients Date of Discovery Unknown Orbit Size Around Sun (semi-major axis) Metric: 149,598,262 km English: 92,956,050 miles Scientific Notation: 1.4959826 x 108 km (1.000 A.U.) Perihelion (closest) Metric: 147,098,291 km English: 91,402,640 miles Scientific Notation: 1.47098 x 108 km (9.833 x 10-1 A.U.) Aphelion (farthest) Metric: 152,098,233 km English: 94,509,460 miles Scientific Notation: 1.52098 x 108 km (1.017 A.U.) Sidereal Orbit Period (Length of Year) 1.0000174 Earth years 365.26 Earth days Orbit Circumference Metric: 939,887,974 km English: 584,019,311 miles Scientific Notation: 9.399 x 108 km Average Orbit Velocity Metric: 107,218 km/h English: 66,622 mph Scientific Notation: 2.9783 x 104 m/s Orbit Eccentricity 0.01671123 Orbit Inclination 0.00005 degrees Equatorial Inclination to Orbit 23.4393 degrees Mean Radius Metric: 6,371.00 km English: 3,958.8 miles Scientific Notation: 6.3710 x 103 km Equatorial Circumference Metric: 40,030.2 km English: 24,873.6 miles Scientific Notation: 4.00302 x 104 km Volume Metric: 1,083,206,916,846 km3 English: 259,875,159,532 mi3 Scientific Notation: 1.08321 x 1012 km3 Mass Metric: 5,972,190,000,000,000,000,000,000 kg Scientific Notation: 5.9722 x 1024 kg Density Metric: 5.513 g/cm3 Surface Area Metric: 510,064,472 km2 English: 196,936,994 square miles Scientific Notation: 5.1006 x 108 km2 Surface Gravity Metric: 9.80665 m/s2 English: 32.041 ft/s2 Escape Velocity Metric: 40,284 km/h English: 25,031 mph Scientific Notation: 1.119 x 104 m/s Sidereal Rotation Period (Length of Day) 0.99726968 Earth days 23.934 hours Minimum/Maximum Surface Temperature Metric: -88/58 (min/max) °C English: -126/136 (min/max) °F Scientific Notation: 185/331 (min/max) K Atmospheric Constituents Nitrogen, Oxygen Scientific Notation: N2, O2 By Comparison: N2 is 80% of Earth's air and is a crucial element in DNA.