Encyclopedia > Lunar day

  Article Content

Lunar day

In space exploration, a lunar day is the period of time it takes for the Moon to complete one full rotation on its axis. Equivalently, it is the time it takes the Moon to make one complete orbit around the Earth, due to tidal locking. It is marked from a New Moon to the next New Moon.

By Earth's time standards, a lunar day is officially 29 days, 12 hours, 44 minutes and 3 seconds long.

In lunar calendars, a lunar day or tithi is defined as one 30th of a lunar month , or the time it takes for the longitudinal angle between the moon and the sun to increase by 12°. By this definition, lunar days vary in duration (see tithi.)

All Wikipedia text is available under the terms of the GNU Free Documentation License

  Search Encyclopedia

Search over one million articles, find something about almost anything!
  Featured Article
Dennis Gabor

...     Contents Dennis Gabor Dennis Gabor (Gábor Dénes) (1900-1979) was a Hungarian physicist. He invented holography in 1947, for whic ...

This page was created in 74.9 ms