Dr. Michael Shara, an astrophysicist from the American Museum of
Natural History, says:
What's gravity all about?
All objects are attracted to or pulled closer to all other objects. Jump up high. Why do you come back down to the Earth instead of floating up into the sky? It's because Earth's strong gravity pulls on you.
You and the Earth are attracted together by gravity, and so is everything else in space: stars, planets, asteroids - even galaxies themselves pull and are pulled by this force. Think of this: if everything in space could stop and stand still for just a second, the very next second every single thing would be in motion again because of gravity.