2007-01-24 09:25:51 · 10 answers · asked by Larz Sasuke 1 in Science & Mathematics ➔ Astronomy & Space
About once a month, or to be precise, once every 29.53 days on average.
2007-01-24 09:30:17 · answer #1 · answered by Keith P 7 · 0⤊ 0⤋
Although it takes only 27.322 days on average for the Moon to complete one orbit around the Earth (the sidereal month), as a result of the Earth's orbital motion around the Sun it requires about two additional days for the Earth, Moon and Sun to acquire the same relative geometry. So on average the number of days between two similar phases (e.g. between one full moon and the next full moon) is about 29.531 days. This period is referred to as a lunation, lunar month, or synodic month. The actual number of days in a lunation can vary from about 29.272 to 29.833 because the velocities of the Moon and of the Earth are not constant in their elliptic orbits, and because of gravitational interactions with other bodies in the solar system. [1][2]
Because the month of February has only 28 days (or 29 in a leap year), there have been a few occasions during which this month has been without a full moon. In particular, there was no full moon in February of 1866, 1885, 1915, 1934, 1961 or 1999. In these years, there were instead either two full moons in January, March, or both (as in 1999). In the leap year of 1972, there was a full moon on February 29.
2007-01-24 10:00:05 · answer #2 · answered by srrl_ferroequinologist 3 · 0⤊ 0⤋
Accure?
A full moon occurs 33 times every 32 months.
2007-01-24 09:30:31 · answer #3 · answered by Anonymous · 0⤊ 0⤋
The exact period varies. This period is called a "synodic month", and can be as short as 29.27 days to about 29.83 days.
The long-term average duration is 29.530 588 days (29 days 12 hours 44 minute 2.8 seconds), or about 29 ½ days.
2007-01-24 09:37:00 · answer #4 · answered by morningfoxnorth 6 · 0⤊ 0⤋
Once a month. Occasionally a full moon will occur twice in the same month....that's called a "blue moon." Hence the phrase, "Once in a blue moon."
2007-01-24 09:33:20 · answer #5 · answered by Anonymous · 0⤊ 0⤋
About every 28 days
2007-01-24 09:30:40 · answer #6 · answered by Cantad al Senor!!!! 2 · 0⤊ 1⤋
About every 28 days.
2007-01-24 09:30:27 · answer #7 · answered by smartypants909 7 · 0⤊ 1⤋
Approx. once every 28 days
2007-01-24 10:02:45 · answer #8 · answered by rosie recipe 7 · 0⤊ 1⤋
once every 28.25 days
2007-01-24 09:30:03 · answer #9 · answered by pjack160 2 · 0⤊ 1⤋
How often does your girlfriend get her period?
2007-01-24 09:52:27 · answer #10 · answered by Anonymous · 0⤊ 2⤋