why is the moon sometimes full and sometimes its half?

Answer 1

The true answer is that the moon has phases because, in addition to orbiting the earth, it orbits the sun with the earth. The part of the sun that you see lit is the part that the sun is shining directly onto. At times we see the full moon because the earth is positioned in space to see more of the lit surface. When we see half, quarter, or sliver moons we are farther behind it relative to the sun and therefore we only see the back. It's like standing in front of the person getting their picture taken or behind them. You see more of them lit up from the front.

The only time the earth ever blocks sunlight to the moon is during a lunar eclipse. While this does happen with some frequency, it is not the cause of the phases of the moon.

Answer 2

Starting with the full moon - A day or two before the "full moon" you will see the
moon rise just before sunset. At full moon it will rise as the sun sets, and of course
after the sun sets as the time goes on. Each night after, notice how the light on the
moon shrinks from full to last quarter and then to nothing (a 2 week time period).
Also during this time you will notice the moon "traveling" closer to the sun.
Two weeks from full moon (day may vary) look for the sliver of the moon just before sunset.
As the moon moves into NEW moon and you cannot see at all, watch for it to become noticable
as a sliver in the other direction as the sun sets. Follow the light on the moon as
it expands to first quarter and then to full. So you can actually see the moon and the sun
at the same time virtually most of the month.

Answer 3

Basically as the moon orbits the earth we see the day and night sides of the moon to varrying degrees. When the moon is between the earth and the sun, all we can see is the night side of the moon so we can't see it at all. When the moon orbits to where the earth is between the sun and moon we see the day side of the moon, thus a full moon. When the moon orbits to where there is a 90 degree angle between the sun, earth, and moon then we see exactly half the day side of the moon and half the night side of the moon, so we only see the half of the moon that is lit up by the sun. If you want to see this effect for yourself, go into a dark room and turn on one light. Hold your fist up to the light, see how it looks dark since you're seeing the side of your fist that is not facing the lighbulb? The bulb represents the sun, your fist the moon, and you are earth. Turn 90 degrees (1/4th) the way around and then look at your fist. See how it is only half lit? Spin around and watch as your eyes see more or less of your fist lit up by the lightbulb. The same principle applies to the moon and its phases.

Answer 4

It is often thought that the Earth casts a shadow on the moon causing the 'phases'. This is far from reality.

As the Moon rotates, albeit very slowly compared to Earth, it experiences it's own days and nights. What we see from Earth is just this. When it's a full Moon, we see the 'day side' of the Moon. When first quarter, half or anything but a full Moon, we see both the day and night sides of the Moon. When it's a new Moon (ie we can't see the Moon), the night side is facing us. And the far side of the Moon would be the day side facing the Sun.

Answer 5

Light from the sun reflects off it different throughout the month depending on it position in relation to the sun and earth. What ever part of the moon that is illuminated by the sun is what you see. During a full moon the moon is on the opposite side of the earth from the sun. The moon is never really "half" it's either first quarter or third quarter; illuminated on one side or the other.

Answer 6

PLEASE IGNORE SCREAMING EAGLES REPLY. The phases of the moon have nothing to do with the shadow of the Earth. It is so simple, you should be able to work it out for yourself. The sun can only shine on one half of the moon (or any moon or planet). That is why we have night and day on Earth (surely you know that?) Therefore, the phases of the moon are simply how much or how little we can see of that illuminated half of the moon. If the sun is behind the moon we don't see any of the moon (new moon) If the sun is on the opposite side of the Earth to the moon, we see all of the moon (full moon) All other positions enable us to see various stages of illumination. It alters from day to day, and goes through the whole cycle (new to new) in about 28 days.

Answer 7

Lunar phases are the result of the sun illuminating the moon at different angles as the relative positions of the sun, Earth and moon change.

Answer 8

I used to wonder how the cesent shape was formed by the light of the sun falling directly on the moon ....it seemed it should always be a straight line dividing dark and light.....it was made clear by shining a bright flashlight on a basket ball in a dark room. You will see it clearly if you try this.

Answer 9

Because sometimes the Earth casts a shadow on the moon and sometimes it doesn't depending on where they are in relation to the sun.

Answer 10

Well, somedays the sun is really close to the moon and it burns some of it up so it gets smaller.
So! you may ask, how does it get big again??
Well, the moon builds itself back together. It grows back.

lol