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The Moon

Moon of Earth

Proper NameThe Moon
Primary PlanetEarth
Orbital Period27.4 days
Distance from EarthSemi-Major Axis: 384,748 km
Perigee: 363,625 km
Apogee: 405,871 km
Eccentricity0.0549 (mean)
Rotation Period655 hours, 43 minutes
MagnitudeFull: -12.6, New: -2.5
Mean Diameter3,476 km
2,159 miles
Map of the Moon Map of the Moon

Key features on the visible face of the Moon.

The single large moon of the planet Earth. A cratered and barren body, its orbit is such that, within certain minor variations, it always shows the same face towards its mother planet.

Image of the Moon

The Moon, as seen from a nearby watery planet.

A New Moon

The first sliver of a New Moon, when the Moon begins to move away from the Sun in the sky, appears at intervals of about 29½ days. This regular event forms the basis of some of Earth's oldest calendars.

Size of the Moon

Earth's moon in comparison with its mother planet: its diameter is less than one third that of Earth.


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