Explaining The Universe on Instagram: "Gravity is the natural force that pulls objects toward one another. It’s what gives weight to everything with mass and keeps planets, moons, and stars in motion. On Earth, gravity pulls everything toward the planet’s center, which is why things fall when dropped and why we stay firmly on the ground. The strength of gravity depends on two things: the mass of the objects and the distance between them—the more massive something is, or the closer it is, the str