When we look out in space everything looks really large, big, incomprehensibly ginormous! We watch movies of space and humans are just tiny little specks in an ocean of "nothingness". Does that mean there is no gravity because there is only space? Nope, gravity is everywhere! When two objects are far from each other the force of gravity is weak, but gravity is still there. All celestial objects in space are basically "falling". They are falling towards Earth, falling toward the Sun, falling toward the galactic center of the universe. All these objects look like they are floating around in space, but really they are falling around in space. Because space is so empty when you are falling there aren't any landmarks around you to help you see how fast you are falling. If you jump off a bridge you can feel the wind and see the water coming at you pretty fast. This fall takes seconds. In space you might be falling for hours, days, years, maybe even eons before you fall into a planet. (Of course, you would have to plan your fall so you fall in the right place on the planet...) Another problem with space is that planets usually orbit something, like a star. Objects that come close to planets usually "sling shot" in curved paths around planets. It's difficult hitting a planet because there are factors like, "inertia" and mass involved. So objects fall in circles around planets. Scientists call this "free falling". The objects experience Earth's or that planets gravity, it is the speed of the object that keeps it from hitting the Earth or planet. Look closely at this lonely drawing. It shows the Sun and Mercury to scale. That's a tiny Mercury, and that's a lot of empty space between them. Mercury is "free falling" around the Sun because of the Sun's gravity and Mercury's speed going around the Sun. Galaxies are held together by strong gravitational forces....so you see, gravity is everywhere. Really.
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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 |