Moon and earth Questions?

Question

I am studying the Moon, sun and Earth. Here are my questions:

1) Why does the moon's phases change?

2)How long would a day be if the Earth was not rotating on its axis?

Thanks!

Answer 1

The moon's phases change because it orbits the Earth. As it moves in it's orbit, we see more, or less of the sun-lit side of the moon.

If the earth weren't rotating at all, that means, the same side of the Earth *always* faced one particular star, the day would equal the year - 365 1/4 days.

Answer 2

1) The Moon's phases make sense if you mentally keep the Sun in one position in the sky and let the Moon move around the Earth. Pretend the Earth has nearly stopped turning and it's always sunset. The Sun just sits on the Western horizon. At New Moon, the Moon is right next to the Sun and we can't see it because most of the sunlight is on the back side of the Moon.

Then slowly, as the Moon drifts toward the East, we start to see the sunlit side, just a sliver. When the Moon is directly overhead, we can see exactly half of the sunlit side because Earth and the Moon are the same distance from the Sun. That's First Quarter.

Then the Moon moves to the far side of the sky, opposite the Sun. When it reaches the Eastern horizon, we can see the entire sunlit side because we're between the Moon and the Sun. That's Full Moon (We might even see a lunar eclipse if we're lined up right.)

Now there's a problem with our mental experiment. The Moon goes over the horizon and we can't see it. If we could, we'd see everything happening backwards, as the Moon gets closer to the Sun and we see less and less of the sunlit side. That's why few people see the Last Quarter, because it only happens late at night.

Finally, when the Moon has made it all the way back to the Western horizon and is between us and the Sun, we have the New Moon again. Each phase of the Moon can only rise at a particular time. A First Quarter rises at noon, A Full Moon at sunset, a Last Quarter at midnight and a New Moon at dawn.

2) Speaking of the Earth stopping, if the Earth did not rotate on its axis, a day would be one year long. A day and a night would each last about 182 days.

Answer 3

1- because of it's relationship to the sun and it's orbit around
the earth.
2- if the earth did not rotate half of the earth would be in darkness 24/7 and the other half would always be in light,
which would probably disrupt weather systems worldwide to
point that would make life almost impossible to exist.

Answer 4

2) there wouldn't be a day cause the sun would be giving light to only one hemispheres.

1) it changes because the sun hits a certain part only lighting up certain part of the moon. like when there is a full moon, the sun is lighting up all the part of the moon we can see.

if this is the wrong answer, im truly srry. i really think this is the answer

Answer 5

John W puts it most succinctly.