Moon

The Earth's moon. Galileo observed the moon through a telescope and thought that the dark areas were seas. This is why some areas of the Moon are named as seas.

A view of the Apollo 11 lunar module "Eagle" as it returned from the surface of the moon to dock with the command module "Columbia". 21 July 1969

Click on an item to paste into clipboard or use clipboard symbol at end to clipboard all values

Mass	7.3483E+22	kg	Clip
Equatorial diameter	3474800	m	Clip
Mean orbital radius	384400000	m	Clip
Orbital period	27.32166d	y=Earth year, d=Earth day	Clip
Gravity at equator	1.62	ms-2	Clip
Mean orbital velocity	1030	ms-1	Clip

paste all data into clipboard

Waning Moon

The moon between full and new when its visible part is decreasing.

See also: Earth, Halo, Metonic Calendar, Selenoid, Selenology, Sun.

Weblinks:
• NASA Photographic Library Photographs from NASA available for viewing and download.
• Phases of the Moon US Naval Observatory Astronomical Applications Department.
• Apollo Image Archive A digital archive of all the original Apollo flight films.