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How the Moon Affects the EarthBy Cindy Grigg

Photo credit: NASA

You already know that the moon'sgravity pulls on Earth's oceans andcauses tides. But the moon affects Earthin other ways, too. Here are a few thingsyou may not know about our moon.

Many scientists believe that someobject the size of the planet Mars hitEarth. It may have been a comet or anasteroid, but whatever it was, it knockeda huge chunk of Earth into space. Thischunk became our moon. The collision caused Earth to tilt sidewaysslightly on its axis, giving us our seasons of spring, summer, fall, andwinter.

Some scientists believe that the moon's gravity has slowed thespeed of Earth's rotation on its axis. Days that used to be ten hourslong are now twenty-four hours. The speed of rotating once in onlyten hours caused winds of up to 125 miles per hour on Earth.Slowing the rotation speed slowed wind speeds. This, in turn, gaveus milder weather.

The moon's gravity pulls on Earth and helps it spin without muchwobbling on its axis. It gives Earth a more even climate. Morewobbling might cause more severe weather events on Earth.

The moon may well have been a part of the Earth at one time.Now the two are close neighbors in space. Because of the closerelationship, the Earth pulls on the moon, and the moon pulls on theEarth. We see this pulling in the ocean tides. There are unseeneffects, too.

How the Moon Affects the Earth

Questions

1. What was one effect of Earth being hit by an asteroid orcomet?

A. the moon's gravityB. seasons on the moonC. ocean wavesD. seasons on Earth

2. Moon's gravity pulls on Earth and prevents ______ that mightcause more severe weather events.

A. spinningB. tidesC. wobbling

3. One effect of the moon on Earth's oceans is ______.

A. tidesB. hurricanesC. tsunamisD. none of the above

4. Do you believe that Earth's slower rotation had a good or badeffect on Earth?

5. List the effects of the moon on Earth. (There are fivementioned in the story.)

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It may be difficult to understand the moon's effects on Earth. Write aletter to a student in a younger grade to explain the moon's effects onEarth in your own words.