How do objects in space travel?
Orbits are the result of a perfect balance between the forward motion of a body in space, such as a planet or moon, and the pull of gravity on it from another body in space, such as a large planet or star. An object with a lot of mass goes forward and wants to keep going forward; however, the gravity of another body in space pulls it in. There is a continuous tug-of-war between the one object wanting to go forward and away and the other wanting to pull it in.
These forces of inertia and gravity have to be perfectly balanced for an orbit to happen. If the forward movement (inertia) of one object is too strong, the object will speed past the other one and not enter orbit. If inertia or momentum is much weaker than the pull of gravity, the object will be pulled into the other one completely and crash.
Is there gravity in space?
What is an orbit?
What is a satellite?
What is gravity?
How do we put a spacecraft into orbit?
Once a ship is in orbit, do we have to do anything to keep it there?
How can a spaceship leave orbit?
How do asteroids orbit?
How does speed affect an orbit?
What is mass?
Are there orbits within orbits?
Can gravity affect the surface of objects in orbit around each other?
What are some kinds of orbits?
What is inertia?
What could cause an orbit to fail?
How do spacecraft use an orbit to move from planet to planet?