CK12 Earth Science

(Marvins-Underground-K-12) #1

there is no wind, rain, or living thing to disturb them. Only a fallingmeteoriteor other
matter from space could destroy them. A meteorite is a piece of rock that reaches the Moon
from space. Meteorites also hit the Earth sometimes.


Earth has mountains, valleys, plains and hills. This combination of all of the surface features
of an area of land is called alandscape. The landscape of the Moon is very different from
that of Earth. The lunar landscape is covered bycraterscaused by the impacts of asteroids
and meteorites that crashed into the Moon from space (Figure24.15). The craters are bowl-
shaped basins on the Moon’s surface. Because the Moon has no water, wind, or weather the
craters remain unchanged. If Earth did not have plate tectonics, which continually alters
the planet’s surface, or an atmosphere, which makes erosion possible, our planet’s surface
would be at least as covered with meteorite craters as the Moon’s. The surfaces of many
other moons orbiting other planets have been shaped by asteroid impacts.


Figure 24.15: A crater on the surface of the Moon. ( 5 )

WhenyoulookattheMoonfromEarthyounoticedarkareasandlightareas. Thedarkareas
are calledmaria. They are solid, flat areas of basaltic lava. From about 3.0 to 3.5 billion

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