In this topic you will learn about how the movement of the Moon around Earth results in some interesting patterns.

The Moon revolves around Earth and Earth revolves around the Sun. You know that the Moon changes its appearance in monthly cycles. The amount of the bright part of the Moon changes shape. The phase of the Moon is the shape of the lighted part of the Moon seen from Earth at any given time.

Half of the Moon is always lighted by the Sun. However, you can't always see all of that half. Sometimes you can see only small amounts of this portion of the Moon. The phase or shape of the Moon depends on the position of the Sun, the Moon, and Earth with respect to each other.

The plane of the Moon's orbit is tilted to the plane of Earth's orbit around the Sun. As a result, the Moon is usually above or below Earth's orbit. Twice a month the Moon crosses the plane of Earth's orbit. When this takes place at full Moon, a lunar eclipse occurs. The view of the full Moon is blocked. A lunar eclipse is a blocking out of a view of the full Moon when the Moon passes into Earth's shadow.

A solar eclipse is a blocking of the view of the Sun when Earth passes through the Moon's shadow. For a solar eclipse to occur, the Moon must be in a straight line between the Sun and Earth. This arrangement happens at New Moon phase. At the greatest part of the eclipse, the Moon completely hides the Sun. All you can see are the gases in the outer atmosphere surrounding the Sun.

Tide is the regular rise and fall of the water along a shore. Tides are caused by gravity. Gravity causes Earth's water to appear stretched. Tides are caused primarily by the Moon. The Sun also affects tides.

Craters on the Moon were formed by the impact of objects from space. Craters are in many shapes and sizes. Some craters seem to have rings that make them look like bulls-eye targets. When the meteorites hit the surface, the impact sent out waves. The waves froze into place. There are more craters on the Moon than on Earth because erosion on Earth wears away Earth craters. There is no erosion on the Moon.