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## Inverse square gravityEdit

The gravitational acceleration towards an object is given by:

$\mathbf{g}=-{mG \over r^2}\mathbf{\hat{r}}$

where:

m is the mass of the object,
r is the distance from center of mass of the object to the location we are considering,
$\mathbf{\hat{r}}$ is the unit vector from center of the object to the location we are considering,
G is the gravitational constant of the universe.

Body Multiple of
Earth gravity
m/s² Satellite/Ring
Sun 27.90 274.1
Mercury 0.3770 3.703 no/no
Venus 0.9032 8.872 no/no
Earth 1 (by definition) 9.8226
Moon 0.1655 1.625 yes/no
Mars 0.3895 3.728 yes/no
Jupiter 2.640 25.93 yes/yes
Saturn 1.139 11.19 yes/yes
Uranus 0.917 9.01 yes/yes
Neptune 1.148 11.28 yes/yes
Pluto 0.0621 0.610 yes/no

 Astronomic object Gravitational acceleration(at surface) Earth g  = 9.80665 m/s2. Moon 0.1654 g Mars 0.38 g
Planetary attributes
Name Rotation period (days) Equatorial diameter
(biq,shortest distance)
Surface
Gravitational acceleration
Sun Sun 25~35 109
Terrestrials Mercury 58.64 0.271
Venus -243.02 0.605
Moon 27.3 2.626 0.1654 g
Earth 1.00 1.00 g = 9.80665 m/s2
Mars 1.03 0.292 0.38 g
Gas giants Jupiter 0.41 4.508
Saturn 0.43 3.176 0.0591g
Uranus -0.72 1.077
Neptune 0.67 0.896

a  Measured relative to the Earth.
b  See Earth article for absolute values.