- from Solar System
In the solar system, nothing ever stands still—not even you.
You and everything else on Earth are traveling up to 1,000 miles per hour right now! That’s how fast our planet’s surface is rotating, or spinning, at the equator. Other planets and moons rotate, too, and even the Sun itself rotates.
While these objects spin, they revolve around, or orbit, each other. The Moon orbits the Earth, and the Earth revolves around the Sun—as do other planets, their moons, and asteroids.
Sometimes these rotating, orbiting, moving objects collide with each other in space. Comets collapse into planets, and asteroids go careening into moons. Why don’t all these planets, moons, and asteroids just stay where they are? The answer is gravity. All objects attract other objects toward them, and the objects that have more mass (or matter) have more power to hold onto things and pull them in.
The Sun contains 99.9 percent of all the matter in the solar system. Everything else makes up just 0.1 percent. So the Sun is the most massive thing in the neighborhood, with a pull so strong that it can even “grab” comets millions of miles away. The Sun’s gravity holds this solar system together and, in fact, it’s the reason we even have a solar system.