ARTIFICIAL SATELLITES:

Satellites are objects that circle around the Earth. They are placed into space by rockets and are held in circles by the gravitational draw of the Earth. The low flying Earth satellites have speed increase 9.8ms⁻² towards the focal point of the Earth. In the event that they don't, they would take off in an orderly fashion digression to the circle. Whenever the satellite is moving all around, it has a speed increase v²/r. In a round circle around the Earth, the centripetal speed increase is provided by gravity.

Close circling satellites circle the Earth at a stature of around 400 km. 24 such satellites structure all the Global Positioning System. An aircraft pilot, mariner or some other individual can now utilize a pocket size instrument or cell phone to observe his situation on the Earth's surface to inside 10m precision.