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There are two phases of half moon, known as first quarter and third quarter. At first quarter, the Moon is one quarter of its journey around Earth, measured from new moon. If you look straight at a first quarter half moon, the Sun should be about 90° to your right, and you would see it in the evening. At third quarter, the Moon is three quarters of its journey around Earth, measured from new moon. If you look straight at a third quarter half moon, the Sun should be about 90° to your left , and you would see it in the early hours of the morning. We don't see that as often, as we are more likely to be in bed. If you look carefully and the conditions are right, you will see half moons during daylight.
We see the illuminated side of the moon as a 50% crescent during the First Quarter and Third Quarter phases. In the First Quarter, the right half of the moon is illuminated, while in the Third Quarter, the left half is lit up. These phases occur approximately a week apart in the lunar cycle, which lasts about 29.5 days.
This is the first quarter phase. The moon looks half lit, half in shadow, but you actually can only see one quarter of the moons surface at this point (during a full moon, you would only be able to see half of the moons surface - the half that faces us).
At "half Moon" we see half of the Moon's hemisphere that is facing Earth. But "half Moon" isn't what astronomers call that phase of the Moon. It is called a "quarter Moon" phase. That's because the Moon has completed one quarter (at First Quarter phase) or three quarters (at Third Quarter phase) of an orbit around the Earth since new Moon. (Another possible reason is that we see a quarter of the total surface of the Moon at these phases.)
Half of the Moon you cannot see because it faces away from Earth. Half of the side you could see is in darkness at "half Moon". That makes 3/4 of the Moon invisible and 1/4 visible. Hence "a quarter Moon" is visible. Another viewpoint: No, that's not really the answer. This is the answer: Let's start with "New Moon". Later, at "Full Moon", the Moon is halfway through its cycle of phases. Halfway between these two phases we see a half Moon. That's called the "first quarter" phase, because the Moon is a quarter of the way through its phases. So, that's why we see the half Moon at a "quarter" phase. It does cause confusion.
The amount of the lighted side of the moon you can see is the same during the first quarter and the last quarter phases. In both phases, half of the moon's illuminated side is visible from Earth.
You can see the same amount of the moon during the first and last quarter, as well as during each half.
The amount of lighted side of the moon you can see is the same during first quarter and third quarter phases. These phases occur when half of the moon's surface is illuminated, and they represent the halfway points between new moon and full moon phases.
50%
Exactly 50% of the moon is illuminated by the sun at every instant of time (except during a lunar eclipse).From our vantage point on earth, the amount of the illuminated half that we can see at any time changesduring the month."First Quarter" means the first quarter of the moon's entire cycle of phases ... about 7.4 days after the"New Moon". At that time, we see half of the illuminated part of the moon ... you'd call it a "half moon".
You see the shadow of Earth cast upon the moon. The Sun's light creates the shadow and illuminates the quarter moon you see.
There are two phases of half moon, known as first quarter and third quarter. At first quarter, the Moon is one quarter of its journey around Earth, measured from new moon. If you look straight at a first quarter half moon, the Sun should be about 90° to your right, and you would see it in the evening. At third quarter, the Moon is three quarters of its journey around Earth, measured from new moon. If you look straight at a third quarter half moon, the Sun should be about 90° to your left , and you would see it in the early hours of the morning. We don't see that as often, as we are more likely to be in bed. If you look carefully and the conditions are right, you will see half moons during daylight.
First Quarter occurs when the moon is at right angles with respect to the Earth and sun. During this phase, the moon has completed one quarter of it's orbit around the Earth and an observer on Earth will see half of the moon illuminated.
At the moments of First Quarter and Third Quarter, the half-disk that you see is 50% of the "light side" ... half of the moon's illuminated surface. The entire moon is still there in the sky. The 'missing' half of the disk is comprised of half of the moon's dark side, which you can't see at that time. Because it's dark !
Both the 1st Quarter moon and the 3rd (last) Quarter moon can be referred to as the "half moon" since we see half of the sunlit side of the moon.
The moon is often visible in the morning, particularly during the waning phases. The time the moon rises and sets depends entirely on it's phase, thus it is not really possible to see a waxing moon during the morning (except when the first quarter moon rises). The two best phases of the moon to see in the morning is the Third Quarter moon and the Waning Crescent moon - since the Waning Gibbous moon sets shortly after sunrise.
Quarter Moon.