1. Earth’s Moon The moon is 384,400 km from the Earth. The moon does not have an atmosphere, so the temperature varies from 130°C in sunlight to -180°C at night.

2. Formation of the Moon Scientists hypothesize that the moon formed after an enormous collision early in Earth’s history.

3. Phases of the Moon The moon’s phases are caused by changes in the relative positions of the moon, sun, and Earth as the moon revolves around Earth.

4. Eclipses An eclipse occurs when the shadow of one body in space, such as a planet or moon, falls on another. For an eclipse to occur on Earth, the sun, moon, and Earth must all lie along a straight line.

5. Eclipses A solar eclipse occurs when the moon casts a shadow on a portion of Earth’s surface.

6. Eclipses A lunar eclipse occurs when Earth casts a shadow on the moon.

7. Tides on Earth Tides are the regular rise and fall of ocean waters. Tides are caused mainly by differences in the moon’s gravitational pull on Earth.

8. Tides on Earth The combined forces of the moon and sun produce a spring tide, when the difference between daily high and low tides is the greatest.

9. Tides on Earth A neap tide is when there is the least change between daily high and low tides. This occurs during the first or third quarter of the moon.