How do objects travel in space?

Objects in space follow the laws or rules of physics, just like objects on Earth do. Things in space have inertia. That is, they travel in a straight line unless there is a force that makes them stop or change. The movement of things in space is influenced by gravity. Gravity is an important force that can change the course of bodies in space or pull them off of one course, or even cause them to crash together.

While some objects in space travel in irregular paths, most (especially our near neighbors in space) tend to travel in orbits around the Sun or around planets. The orbits are usually close to circular, but are actually slightly flattened ellipses.

Ask any question below to learn about travel in space.

What is an orbit?
What causes an orbit to happen?
What travels in an orbit?
How do scientists know what the path of an object in space will be?
How does gravity work in space?

How is an ellipse different from a circle?
Are there orbits within orbits?
Are there orbits within orbits?
What is inertia?

What's a gravity well?
How do we know what's in space?