Moon

Moon

The Earth's only natural satellite. The moon has a cold, dry orb covered with many lunar craters and strewn with rocks and dust. The moon has no atmosphere. But recent lunar missions have found plenty frozen water on the moon.

Industry: Astronomy

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Moon

Earthshine

Astronomy; Moon

The light of the sun that is reflected back into space by the Earth, and which can illuminate other objects such as the Moon. Earthshine can illuminate a young crescent moon so that the whole face ...

Penumbra

Astronomy; Moon

The name given to the shadow cast by a celestial object that only blocks a portion of the light.

Perigee

Astronomy; Moon

The point in the Moons orbit when it is closest to the Earth (opposite of apogee).

Parallax

Astronomy; Moon

The apparent motion of an observed object against the background caused by the movement of the observer. An example of this is the motion of the stars as seen from observatories on Earth.

Partial eclipse

Astronomy; Moon

A lunar eclipse in which the Moon only partly enters the dark, umbral shadow of the Earth but is inside the secondary, penumbral shadow. Also refers to a solar eclipse when the Moon does not line up ...