how many days before the moon changes shape?

Question

How many days apart is a half moon from a full moon

Answer 1

I think next week it turns into a trapezoid. The parallelogram phase comes after that.

Answer 2

A full cycle of moon phases (new to new) is, on average, about 29 1/2 days. So each quarter (new, first, full, last) is about 7 or 8 days after the previous one. On the calendar it may look like more or less because these are not exact days.

If a first quarter happens at 10:15PM on the 6th and the full moon happens at 2:45 AM on the 14th, that's 8 calendar days but only 7 1/2 real days. So it helps to know at what hour a phase is occuring, not just the day.

Even then, the moon's orbit is not perfectly round, so it slows down as it moves outward and speeds up as it moves in, so you can't just mark a phase and count a certain number of days, hours and minutes to get the next phase. You have to account for orbits too. And if your calendar is a diferent time zone than yours, it may show a phase on the wrong day for your area. (That's technical, it looks pretty much the same for the few hours difference.)

What makes a phase a phase is where the moon and sun are relative to Earth. At the new moon, the moon and sun appear to be passing each other (and we sometimes get a solar eclipse). At first quarter, the moon is perpedicular to the sun (and rises six hours later, at noon). At full moon, the moon is opposite the sun and rises at sunset (and we sometimes get lunar eclipses). The last quarter is another 90 degree situation, when the moon rises at midnight. Each night, the moon is about 49 minutes further behind the sun in the sky, and after 29 1/2 days, the sun has lapped the moon.

If you were Jewish or Muslim or Chinese, you might have a better feel for the lunar cycle because the months of these calendars always start with a new moon. Holidays based on a lunar calendar move around in the standard Gregorian calendar, which is NOT lunar.

And as others have pointed out, the moon's phase is ALWAYS changing shape. It's not just these four, neat, round/flat divisions. Crescent is a shape, so is gibbous.

So, the simple answer is, 7 days and change per phase. The accurate answer is, look it up in a table or get a software program that will calculate it for you. The URL listed in the sources uses Universal Time, which is like London without the summer adjustment. Subtract 4 hours for Eastern Daylight time, 5 for Eastern Standard, 7 for Pacific Daylight, 8 for Pacific Standard.

Answer 3

basically the moon doesn't change shape at all, it's shadow just moves around it about 14 1/2 days from a half to full because it takes 29 days for a full moon to appear

Answer 4

The moon does not change shape, but we know what you mean. Actually, the moon is not round. It is shaped like a half fooball with the pointed end always aimed at the Earth - the reason why it never rotates and never shows us its "dark side". The moon is continually showing a slightly different lighted phase in its "lunar month", but we do see eight distinct degrees (called the phases). It is a 29.5 day average cylcle.

Answer 5

According to my calender we are to have a full moon on, Sat.Oct.7th. And the new moon is on Sun.Oct.22nd.From what I've looked before on my calender to check the same thing you are asking.It is usually about 15 days, give or take a day or so. Hope that helps, God bless

Answer 6

7 days

Answer 7

between 14 1/2 day's till it's back moon and then its 14 1/2 days full money again,take care love you could have mood swings from the both especialy if your a cancerian crab;s are hatched during the moon beeing full,

Answer 8

The moon never changes shape. It is always round you just can see part of it because of where the sun is. We only see that part of the moon. It's still round we just can't see it.

Answer 9

a moon cycle is 28 days. So, I would guess that it would take a quarter as long as the cycle. So i would say it would take 7 days, 1 week. :)

Answer 10

Lunar calendar has 30-31 days in a month. So every 15-15.5 days.