Astronomy Picture of the Day
    


Lunation
<< Yesterday 5.02.2012 Tomorrow >>
Lunation
Credit & Copyright: AntÑnio CidadÖo
Explanation: Our Moon's appearance changes nightly. This time-lapse sequence shows what our Moon looks like during a lunation, a complete lunar cycle. As the Moon orbits the Earth, the half illuminated by the Sun first becomes increasingly visible, then decreasingly visible. The Moon always keeps the same face toward the Earth. The Moon's apparent size changes slightly, though, and a slight wobble called a libration is discernible as it progresses along its elliptical orbit. During the cycle, sunlight reflects from the Moon at different angles, and so illuminates different features differently. A full lunation takes about 29.5 days, just under a month (moon-th).

APOD in India: APOD editor to speak in Delhi on Feb. 12 (registration required)

January
February
March
April
May
June
July
August
September
October
November
December
 < February 2012  >
Mo Tu We Th Fr Sa Su


12345
6789101112
13141516171819
20212223242526
272829



Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.

Based on Astronomy Picture Of the Day

Publications with keywords: Moon - lunation
Publications with words: Moon - lunation
See also:
All publications on this topic >>