Space Environment How do objects in space travel?

What is an orbit?

An orbit is a regular, repeating path that an object in space takes around another one. An object in an orbit is called a satellite. A satellite can be natural, like the moon, or human (or extraterrestrial?) -made.

(This drawing is not a scale drawing)
In our solar system, the Earth orbits the Sun, as do the other eight planets. They all travel on or near the orbital plane, an imaginary disk-shaped surface in space. All of the orbits are circular or elliptical in their shape. In addition to the planets' orbits, many planets have moons which are in orbit around them.

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 What causes an orbit to happen?
What is a satellite?
 What travels in an orbit?
 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 is an ellipse different from a circle?
 Are there orbits within orbits?
 What is the orbital plane?
 What are some kinds of orbits?

 What are the orbital lengths and distances of objects in our solar system?
 What could cause an orbit to fail?
 How do spacecraft use an orbit to move from planet to planet? 

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