Directions: Look for facts and details as you read these paragraphs. The Moon is over four billion years old. How the Moon formed remains a mystery. Here are four theories that scientists use to explain the Moon's origin.
The "escape" theory Some scientists believe that Earth and the Moon were once a single body. Earth was spinning much faster than it does today. The Sun's gravitational pull caused a bulge on one side of the rapidly spinning Earth. As the lopsided Earth spun, the bulge eventually broke away to form the Moon.
The "capture" theory Possibly, the Moon was once a planet that traveled around the Sun, just as Earth does. The Moon and Earth had similar orbits. Every few years, Earth and the Moon would come close to each other. One time, their orbits brought them so close that the Moon was captured by the f of Earth's gravity. The Moon then became a satellite of Earth.
The "formation" theory This theory says that the Moon and Earth formed at about the same time. The two bodies were formed from huge whirlpools of gas and dust left over from when the Sun was formed. Earth and the Moon started out as two separate bodies that stayed near each other, similar to a double planet.
The "collision" theory A fourth theory Is that a huge body from space smashed into Earth. The impact was so great that pieces of Earth broke off. These pieces began orbiting Earth. Eventually the material grouped together, forming a single body known as the Moon.
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