how come the moon doesnt always appear full?

Answer 1

the moon revolves around the earth.. but the earth revolves around the sun.. as a result, each month, the earth finds itself between the moon and the sun at various angles at various times. The earth, therefore, blocks the sun's light from reaching the moon at those times. This causes the moon to look half full.. or quarter full.. etc..

Answer 2

Wow! I am disappointed in how many people responded that Earth's shadow causes the Moon's phases! When Earth's shadow falls on the Moon we have a Lunar Eclipse, which is very different from the phases of the Moon.

We see the Moon because it reflects sunlight. Since the Moon is a sphere, half of it is always lit up, just not always the same half. Just like there's always half of Earth in daylight and the other half in darkness. Or, shine a flashlight on a ping pong ball (or anything else that's spherical) and you'll notice half of it lit up, half of it dark.

So half of the Moon is always lit up, but we don't always see the lit-up half. The Moon orbits Earth, but the lit-up part of the Moon always faces the Sun, not Earth, of course. The only time we have a Full Moon is when the Sun, Earth, and Moon make a line - so the Earth is between the Sun and the Moon. Then Earth can see all of the lit up side of the Moon. If the Moon is between Earth and the Sun, then the dark side of the Moon is facing Earth, so Earth only sees the dark side (we call that New Moon, and it isn't really seen at all because it is too dark). All other times we see part of the lit-up side and part of the dark side. As it takes about a month for the Moon to orbit Earth, it takes about a month for the Moon to go through all of its phases, from New Moon, to First Quarter, to Full Moon, to Third Quarter, and back to New Moon again.

Answer 3

The phases of the moon have nothing to do with the earth blocking light from the sun. That is a lunar eclipse. The moon's phases are caused by the moon going around the earth. One side of the moon faces the sun and is visible. At one point in a month, the moon is in a position where the whole light side is facing us and the moon is full. About 2 weeks later, the dark side is toward earth and we have a new moon.

Answer 4

Oh no!

It's not the Earth's shadow (otherwise we'd see eclipses all the time)!
It's just the angle of the Earth to the Moon to the Sun. This can start to sound really complex if I get too into it. Basically if the sun is at a right angle with the Moon and Earth then we see only half of it illuminated.

For it to always be full, the sun would have to always appear at the opposite side of the sky. Since the moon revolves around us at a different rate than we revolve around the sun this is impossible.

Answer 5

there are not an excellent 30 nights, its 29.5 days for the moon. And the earth's axis is tilted slightly. there's no longer 360 days interior the three hundred and sixty 5 days. it could remember on the earth's flow around the solar, seeing this is the earth's direction, after a three hundred and sixty 5 days, it starts this is direction lower back.

Answer 6

when the earth comes between the sun and the moon, then part of the moon is in shadow and thus you see the phases of the moon depending on the position of the earth and moon

Answer 7

Because every month as the earth rotates, it covers part of the sun and the earth's shadow is on the moon.

Answer 8

its the rotation of where the earth sun and moon are aligned

Answer 9

it rotates around the earth and the suns light hits at different areas.

Answer 10

the earth cast it's shaddow causing it to look the way it does