Page 45 - Curriculum Visions Dynamic Book

The Moon’s surface
We depend on our thicker atmosphere to protect us from space, and in particular to make most meteorites burn up before they reach the surface. Since the Moon has no such protective shell, meteorites arriving there collide with the surface, creating impact craters. They are what we can see so clearly from the Earth. It is these impacts that have shattered meteorites and the Moon surface to produce the “soil” that is now found by astronauts. Every part of the surface has extensive impact craters, some small, some enormously large (see pages 50–51). However, there are remarkable differences between the near side (that faces us) and the far side (that we never see from Earth).
apollo The program developed in the United States by NASA to get people to the Moon’s surface and back safely.
atmosphere The envelope of gases that surrounds the Earth and other bodies in the Universe.
crater A deep bowl-shaped depression in the surface of a body formed by the high-speed impact of another, smaller body.
diffraction The bending of light as it goes through materials of different density.
meteorite A meteor that reaches the Earth’s surface. molecUle A group of two or more atoms held together
by chemical bonds.
radioactive The property of some materials that emit radiation or energetic particles from the nucleus of their atoms.
solar wind The flow of tiny charged particles (called plasma) outward from the Sun.
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