If you shine a flashlight upwards, the light will grow imperceptibly redder as gravity pulls it. Albert Einstein discovered this principle. Gravity not only pulls on mass but also on light. Gravity creates stars and planets by pulling together the material from which they are made. The gravitational pull of the moon pulls the seas towards it, causing the ocean tides. Gravity is what holds the planets in orbit around the sun and what keeps the moon in orbit around Earth. But because Earth is so much more massive than you, your force doesn’t really have an effect on our planet. You exert the same gravitational force on Earth that it does on you. And if you were on a planet with less mass than Earth, you would weigh less than you do here. All its mass makes a combined gravitational pull on all the mass in your body.

So, the closer objects are to each other, the stronger their gravitational pull is.Įarth's gravity comes from all its mass. Objects with more mass have more gravity. Image credit: NASAĪnything that has mass also has gravity. If another object is nearby, it is pulled into the curve. Albert Einstein described gravity as a curve in space that wraps around an object-such as a star or a planet. Earth's gravity is what keeps you on the ground and what makes things fall.Īn animation of gravity at work. Why do you land on the ground when you jump up instead of floating off into space? Why do things fall down when you throw them or drop them? The answer is gravity: an invisible force that pulls objects toward each other. The force of gravity keeps all of the planets in orbit around the sun. Gravity is the force by which a planet or other body draws objects toward its center.

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