User:Milton Beychok/Sandbox2

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Revision as of 01:26, 27 June 2011 by imported>Milton Beychok
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Earth's Moon: Facts & Figures
Physical Characteristics
Mean circumference 10,917.0 km
Mean radius 1,737.5 km
Mass 7.3477×1022 kg
Volume 2.197×1010 km3
Density 3.344 g/cm3
Surface area 3.79367×107 km2
Surface gravity 1.624 m/s2
Escape velocity 2,376 m/s
Rotational and Orbital Characteristics
Distance from Earth:
Average
Apogee (farthest)
Perigee (closest)

384,400 km
405,696 km
363,104 km
Rotation velocity around own axis 4.6246 m/s
Rotation period around own axis
(length of Moon day)
655.73 hours
27.322 Earth days
Orbit distance around the Earth 2.4134×106 km
Orbit velocity around the Earth 1.0224 km/s
Orbit period around the Earth
(length of "Moon year") (a)
655.73 hours
27.322 Earth days
Orbit period around the Sun 365 Earth days
13.359 Moon days
(a) Defining a celestial body's length of year as the
time it takes the celestial body to travel one orbit around
a larger celestial body. Thus, the orbit period of the
Moon around the Earth is a "Moon year". It is simply
happenstance that the Moon also takes 27.322 Earth
days to revolve around its own axis and so a "Moon day"
is the same as a "Moon year".