Gravity is the force by which a planet or other body draws objects toward its center. The force of gravity keeps all of the planets in orbit around the sun. Earth's gravity is what keeps you on the ground and what makes things fall.Without gravity, we would float off into space. The force of gravity is what gives us weight. If you were on a planet with less gravity than Earth, you would weigh less than you do here. If you were on a planet with more gravity, you would weigh more.Earth's gravity comes from all its mass. All its mass makes a combined gravitational pull on all the mass in your body. That's what gives you weight. And if you were on a planet with less mass than Earth, you would weigh less than you do here.Gravity is also what keeps the moon in orbit around Earth. And it's what makes it possible for us to have tides. The moon's gravity pulls on the oceans, causing the tides.These are just a few of the many things that gravity does. It's a fascinating force, and scientists are still learning about all its effects.