User:Milton Beychok/Sandbox2: Difference between revisions

Revision as of 01:26, 27 June 2011

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".

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 |Orbit period around the Sun||365 Earth days<br/>13.359 Moon days
 |-
-|colspan=2|(a) Defining a celestial body's length of year as the<br/>time that it takes for the celestial body to travel the<br/>distance of its orbit around a larger celestial body. In<br/> other words, the orbit period of the Moon around the<br/>Earth is the Moon's length of year
+|colspan=2|(a) Defining a celestial body's length of year as the<br/>time it takes the celestial body to travel one orbit around<br/>a larger celestial body. Thus, the orbit period of the<br/>Moon around the Earth is a "Moon year". It is simply<br/>happenstance that the Moon also takes 27.322 Earth<br/>days to revolve around its own axis and so a "Moon day"<br/>is the same as a "Moon year".
 |}