duration of moon phases?

Question

I was wondering if anyone could tell me how long most moon phases last. Is it 2-3 days? Or is it more?

Answer 1

The Moon's phases can be divided into eight phases: 1.New Moon, 2.Waxing Crescent, 3.First Quarter, 4.Waxing Gibbous, 5.Full Moon, 6.Waning Gibbous, 7.Last Quarter, and 8.Waning Crescent.

Technically, each phase lasts only a brief instant. However, since the cycle of the moon is divided over about 29 1/2 days, the change over a few hours is very small. To the unaided eye, the change is imperceptable but a careful observer with a telescope could note the change.

Again, the New Moon phase technically lasts only an instant but to our eyes a New Moon's phase can seem to last for a few days as that would represent the time that the Moon is too close to the Sun's position in the sky for us to see sunlight reflecting off of the Moon's surface.

Answer 2

The moon's phases are gradual.

It take about 28 days to orbit the Earth in which it goes from new (no moon) to full and back to new.

So when you see a half moon, it is really either in its 1/4 phase or its 3/4 phase.

Therefore, there are about 7 days between new moon and first quarter (when the moon looks half). Then 7 days to full. Then 7 days to the 3/4 phase (when it looks like a half moon again) then 7 days back to new.

I would have thought they would teach you this basic stuff at school. But it is simple to work out simply by watching the moon from night to night and recording what you see in a diary.

Answer 3

Technically speaking full moon, new moon, first quarter and last quarter are very short, lasting only an instant each. Full moon is when the Moon is exactly 12hrs of right ascension from the sun in the sky, and therefore the full disc appears illuminated from Earth. New Moon is when the moon is exactly 0hrs of right ascension, hence the illuminated side is turned away from us. First and last quarter are 6 and 18hrs of right ascension respectively, with the terminator appearing as a straight line dividing the disc in half.

(In visual terms, however, it is often easier to consider these phases lasting one day or night each, as the unaided eye won't detect much difference between a rising and setting full Moon or quarter phase, and the new Moon is invisible because the illuminated side faces away from us.)

The waxing crescent phase lasts between new Moon and first quarter, the waxing gibbous phase lasts between first quarter and full Moon, the waning gibbous between full Moon and last quarter, and the waning crescent between last quarter and new Moon.

In very rough terms, then, the crescent and gibbous phases last about a week, while the new, full and quarter phases occur at specific times.

Answer 4

Assuming you mean quarters in the moon phase cycle, they last 7-8 days. This is why you only see a full moon about once every month (28ish days).