it is one half
We see exactly half of the moon illuminated during the First Quarter and Last Quarter phases. In the First Quarter, the right half appears lit, while in the Last Quarter, the left half is illuminated. These phases occur approximately a week apart in the lunar cycle.
The two phases of a waxing Moon are the first quarter and gibbous. During the first quarter, half of the Moon is illuminated and appears as a half-circle in the sky. During the gibbous phase, more than half but not yet fully illuminated, the Moon appears as a large, slightly bulging shape.
A Waxing Gibbous occurs when the moon is illuminated between a First Quarter and a Full Moon, during the second half of the moon's cycle. It appears as a larger part of the moon illuminated, but not yet full.
A quarter moon, also known as a first or last quarter moon, appears as a half-circle or semicircle when viewed from Earth. During the first quarter, the right half is illuminated, while in the last quarter, the left half is lit. This shape results from the relative positions of the Earth, Moon, and Sun.
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".
"First Quarter" is the phase when the moon appears half-illuminated, and rises and sets roughly 6 hours (1/4 day) after the sun.
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.
The first quarter moon occurs when the moon is halfway between the new moon and full moon, and one-quarter of its surface is illuminated. It appears as a half-circle in the sky, with the right side illuminated. It is also known as a half moon.
The Moon is not visible at the new moon phase. At the first quarter, it is "waxing" - the illuminated portion is increasing. At the full, the illuminated portion of the Moon is 100%, and it is finished waxing and is about to begin "waning", when the illuminated part is decreasing. At the 3rd quarter, it is waning.
The four phases of the moon are new moon, first quarter, full moon, and last quarter. During the new moon, the moon is not visible from Earth; first quarter marks the half-illuminated phase; full moon is when the entire face of the moon is illuminated; and last quarter also shows a half-illuminated phase but on the opposite side from the first quarter.
When the moon appears as a half-illuminated disk, and the illuminated portion is growing from one night to the next,the phase is known as "first quarter".
After the first quarter moon comes the waxing gibbous moon. The waxing gibbous moon appears as the illuminated portion of the moon grows larger each night until it reaches a full moon.