Chapter 3 Summary, p.55-71

Target Language or Knowledge:

Gravity is a force of attraction between any two objects, caused by those objects pulling on each other. The earth revolves around the sun once about every 365 days. The moon revolves around the earth once about every 29 days. The changes in the moon's appearance are the phases of the moon. The moon's surface has dark areas including the rims of craters. Craters are caused by rocks, such as meteorites, hitting the moon's surface. A lunar eclipse happens when the earth is between the moon and the sun. A solar eclipse happens when the moon is between the earth and the sun. The moon's surface has dark areas called maria and light areas that are highlands. During the 1960s and 1970s, astronauts walked on the moon, collecting information about it.