Oh peapod83, isn't it marvelous what nature shows us? When you see only half of the moon, it's because of where the sun is shining on it from Earth, creating what we call phases. Just imagine painting a lovely portrait of a half-moon shining brightly in the sky - isn't it a delightful sight? Just as the moon moves gracefully through its phases, remember to be kind, patient, and gentle with yourself as you go through your own changes in life.
A half moonA half moon
Just like the Earth, half of the Moon is lit by the Sun while the other half is in darkness. The phases we see result from the angle the Moon makes with the Sun as viewed from Earth. We only see the Moon because sunlight reflects back to us from its surface.
Well, the moon is a sphere, and if it is a full moon you are really only seing half of it. so technically you are seeing 50% of the moon
You see about 50% of the moon because we are only really seeing half of it because it is a sphere.
The object that blocks the moon when there is a half moon is the moon itself. The moon is a sphere, so only one half of it can be sunlit at any moment. The other half is dark just because the sun is below the horizon for that half of the moon. And when we see a half moon, we are simply looking at the moon just as the line of sunrise/sunset cuts across the moon's diameter.
This is when you can only see half a moon out at night.
quarter moon
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).
The moon is only visible because of the sun's light, which is why the moon appears to glow. When there is a half moon, only half of the moon is reflecting off the sun's light. It all has to do with the angle of the moon, the sun, and the Earth, which is why the moon has so many different phases.
First or Third Quarter
That phase is called the third quarter or it could be called a waning half moon.
Nothing happens to the other side of the Moon in half moon days. The reason we do not see the whole Moon is because only half of it is reflecting the light from the Sun.
During a quarter moon, we see half of the moon's surface lit up by the sun. This is because the angle between the sun, Earth, and moon creates a line where we see only half of the illuminated side.
The light we see from the Sun is from the Sun itself; the entire surface of the Sun is bright. Only half of the Moon is bright, because it is illuminated by the Sun. The sun generates light, the moon can only reflect it, not generate any.
A half moonA half moon
Half-moon Half-Earth
You can often see the entire "near side" of the Moon, because even though the sunlit half is very bright, the other part is dimly lit by reflected Earthlight. However, the official answer to your question is probably "one quarter". You can only see one-half of the Moon, and only half of that is lit up by the Sun.