How are earth and moon related?

They can be thought of as a binary system , in the third orbit from the Sun.

The Earth's Moon is a very big natural satellite compared to other satellites of other planets.

The Moon is approximately one quarter to one third the size of Earth.

Such is the size and gravittional pull , of these two objects, they pull each other in and out of the Earth's mean orbital track.

When you see a nice smooth elliptical diagram of the Earth's orbit about the Sun, this is not quite correct!!!! Because of the Moon's pull , the Earth moves in and out of this ellipse. Also because the Moon's orbit about the Earth is angles at about 5 degrees to the Earth's orbit about the Sun, It also pulls the Earth 'up and 'down' from the plane of this orbit. 'The Earth 'dances' through space , with the Moon as its dancing partner. The whole pair is kept on a mean orbital track by the Sun.

The Moon orbits the Earth once every 28.5 days. It also rotates on its own axis in about the same period. Consequently from Earth we only ever see 61% of the Moon's surface. The other 39% is permanently hidden from view. The Moon's orbit is also elliptical. So at different times and places on this orbit it can be nearer or further away from Earth. When you see a 'big, bright' Full Moon, it is probably at its nearest to Earth.

The Moon also controls the tides at sea. The side of the Earth that the Moon is on , is the high tide side. However, on the opposite side of the Earth there is also a corresponding high tide ; a 'wheel balancing effect'.

The Moon is also thought to control natural phenomena, such as dogs howling , people being mad (lunacy), etc., plant growth and harvest. However, the connection is very tenuous.

So there you have it!!!! I'm sure there is a lot more that can be written about the Earth/Moon partnership!!!!!