Comparison of Mercury and Earth

Mercury, the innermost planet in the solar system, is much smaller than Earth, but the material it is made of is much more dense on average. The table below gives a comparison of characteristics of Mercury relative to Earth values.

Characteristic Relative to Earth
(Earth = 1)
Absolute Value
Mass 0.0553 3.303 x 10**26 g
Radius 0.382 2,439 km
Mean Density ----- 5.43 g/cm**3
Rotation Period 58.65 Earth days -----
Mean Orbital
Distance
0.3871 AU 57.91 x 10**6 km
Orbital Period 87.9 Earth days -----
Mean Orbital
Velocity
1.6 47.89 km/s
(112,000 mi/hr)
Orbital eccentricity ----- 0.2056
Inclination to
ecliptic (degrees)
----- 7.004
Temperature range ----- -360F (-183C) to
840F (450C)


Definitions of planetary characteristics

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