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Planets

Characteristics of Earth

Earth is the largest of the four terrestrial planets. The third planet from the Sun, we have the good fortune to be on a planet that is large enough to hold onto its hydrogen and far enough to have liquid water. Of course the characteristics of the earth are determined to very high accuracy. The biggest error in the values given below is for Earth's mass, and arises from the relatively large error in the value of gravitational constant. In this table, the observed values are taken from Yoder (1995).[1] Go to table.

Characteristics of Earth

GM e

3.98600440×1020 cm3 s−2

Mass

5.972×1027 g

Mean Radius

6.3710(1±2)×108 cm

Equatorial Radius

6.378137×108 cm

Flattening

1/298.257222

Surface Gravity

982.022 cm s-2

Escape Velocity

1.11861×106 cm s−1

Average Density

5.513 g cm−3

Sidereal Rotation Period

23h 56m 04.09054s

86164.09054 s

Obliquity of Ecliptic

23° 26 21.4119

Sidereal Orbital Period

365.242190 d

Semimajor Axis

1.00000011 AU

Eccentricity

0.01671022

Solar Constant

1.3676 × 106 ergs cm−2 s−1

[1] Yoder, Charles F. “Astrometric and Geodetic Properties of Earth and the Solar System.” In Global Earth Physics: A Handbook of Physical Constants edited by T.J. Ahrens, 1–31. AGU Reference Shelf, No. 1. Washington: American Geophysical Union, 1995.

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