Why would something remain in orbit?

Question

Why would something remain in orbit?

Answer 1

Because an orbit is the natural steady-state balance between momentum and gravity.

Orbits decay not because the physical steady state breaks down of its own accord, but because secondary forces like solar wind, perturbation, and drag diminish the momentum component and allow gravity to dominate.

Answer 2

There is no frictionif it is high enough not to enter any of the atmosphere.  

Answer 3

Imagine you put a cannon up on top of a tall mountain and fire a cannon ball off horizontally.

It would go some distance, and then fall to the Earth.

Fire it again, with more gunpowerder, and it will go even further. Imagine that you pack it with so much powder that it flies all the way to the horizon before it really starts falling to Earth. If it "falls" over the horizon, it has effecftively "missed" the Earth and will continue in flying around the Earth, always drawn in by gravity, but never succeeding in hitting the ground!

This is an orbit.

Air friction is a problem, though, and in this case, the ball will quickly fall due to the high air drag within the lower Atmosphere. This problem persists even at higher orbits, and causes most spacecraft's orbits to "decay". The satellites will slowly lose altitude and finally crash into the atmosphere.

At very high altitudes, though, a satellite is likely to orbit for hundreds of thousands of years before decaying.  

Answer 4

When one object is orbiting another object, it is actually free-falling around that object. For instance, an object orbiting the Earth. When something gains enough speed, it will try to fall back to the Earth, but because it is moving so fast, it never hits the Earth's surface. So it keeps going in a steady circle around the Earth, without the use of rocket boosters. It is falling towards the Earth, but never hits it because the Earth is round, so it curves when the object's free fall curves. The way an object comes out of orbit is to change that object's speed. If the speed changes, it automatically drops out of orbit and can come back to Earth or continue in to space. It's a fascinating concept, but it can be confusing!

Answer 5

Only if it has a way to keep itself in orbit such as boosters.  If it is not functioning, the orbit will decay in time and it will fall into the atmosphere and burn on re-entry due to the earth gravitational pull.    

Answer 6

one word: gravity