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20 Cards in this Set
- Front
- Back
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The moon is earth's one and only natural satellite...
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...the moon is an object in orbit around the earth.
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What is the moon?
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The moon is a big ball of solid rock. It's surface is covered with several cm of rock "powder", formed by all of the meteorites that have crashed into the moon over the centuries.
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How long does it take the moon to REVOLVE around the earth?
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It takes 27.3 days for the moon to REVOLVE around the earth.
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How long does it take the moon to ROTATE on it's axis?
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It takes the moon 27.3 days to ROTATE on its axis.
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Since the moon's ROTATION and REVOLUTION times are the same, what happens?
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The moon will always keep the same side facing the earth. From the earth, no one has EVER seen the back side of the moon.
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Since the moon is in orbit around the earth, we will not see it at the same time every day. From one day to the next, the moon will rise on average...
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...50 minutes later than it did the day before.
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What fraction of the earth's size is the moon?
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1/4
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How much of the earth's mass is the moon?
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1/80
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Since the moon's mass and density are both smaller than earth's...
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...the moon will have a weaker gravitational attraction.
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What fraction of the earth's gravity is the moon?
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The moon's gravity is only 1/6 as strong as the earth.
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Will objects weigh the same on both the earth and the moon?
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No, objects on the moon will weigh less than they do on the earth.
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To get the weight of an object on the moon...
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...you take the object's weight on the earth and divide it by 6.
(example: if a person weighed 120 lbs on earth they would weigh 20 lbs.on the moon) |
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What are the lighter areas on the moon called?
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"highlands"
These areas are more rough and uneven...they may be mountainous in some places.) These areas reflect light really well and appear bright when we look at the moon. |
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What are the darker areas on the moon called?
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"maria"
Named by Galileo, maria is the Latin word for "seas", as Galileo thought these were great oceans on the moon. However, they are simply places that were covered by great lava flows millions of years ago. The lava hardened into smooth, dark colored rock which is why these areas appear dark. |
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What are craters?
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Craters are round holes in the moon's surface caused by the impact of meteorites from space.
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What do craters look like?
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Craters come in all sizes. They can be less than a mm across to hundreds of km wide.
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Describe the moon's physical features.
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The moon
1) has NO atmosphere 2) has little water 3) and there is no rain, snow, ice, or wind, so erosion does not occur. |
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Does the surface of the moon change?
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The surface of the moon does not change unless an area is struck by a meteorite from space. This means that footprints left decades ago by astronauts are probably still there today.
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When did we first land on the moon?
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Astronauts 1st landed on the moon in July of 1969, ending a lengthy effort to place people on the moon. Between 1969 and 1972 a total of 12 American astronauts walked on the moon.
They are the only people to ever successfully land on another object in space. They collected numerous rock samples and conducted a variety of experiments. |
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How did the moon form?
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Very early in it's history while the earth was still mostly molten (liquid), it was struck by some other large object. This collision caused large amounts of the earth's molten material to separate from the rest of the earth. Earth's gravity kept this material in orbit around the earth and that material gradually cooled, pulled together, and hardened into solid rock. (Rocks brought back from the moon are perfect matches with rocks found here on earth.)
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