Earth and many other bodies—including asteroids, comets, and the other planets—move around the sun in curved paths called orbits. Generally, the orbits are elliptical, or oval, in shape. Because of the sun’s relatively strong gravity, Earth and the other bodies constantly fall toward the sun, but they stay far enough away from the sun because of their forward velocity to fall around the sun instead of into it. As a result, they keep orbiting the sun and never crash to its surface. The motion of Earth and the other bodies around the sun is called orbital motion. Orbital motion occurs whenever an object is moving forward and at the same time is pulled by gravity toward another object. Just as Earth orbits the sun, the moon also orbits Earth. The moon is affected by Earth’s gravity more than it is by the gravity of the sun because the moon is much closer to Earth. The gravity between Earth and the moon pulls the moon toward Earth. At the same time, the moon has forward velocity that partly counters the force of Earth’s gravity. So the moon orbits Earth instead of falling down to the surface of the planet. There are lots of other objects orbiting our Earth, satellites for instance. Computers have been used to enhance what it would look like if we could see the Earth and all the satellites that orbit Earth... Crazy isn't it? That's a lot of "stuff" orbiting around us, right now! I wonder what the aliens be sayin'?
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Mrs. TaylorI love science! Everything about the world is interesting and never boring. I love to study plants, animals, insects, and people. My favorite subjects are my students who are the most unique organisms on the planet! Categories |