@S1-A.ARPA,@MIT-MC.ARPA:Ayers.PA@Xerox.ARPA (06/02/85)
From: Ayers.PA@Xerox.ARPA In an appropriate (earth-centered, non-rotating) reference frame, any coasting earth-orbiter travels in a closed curve. (We neglect air resistance, the equatorial bulge, the influnce of the sun and moon and planets, light-pressure, and all that other stuff you get to leave out of physics problems.) You are in earth orbit and throw something away from you -- in any direction, forward, backward, up, down ... The instant after the throw, both you and the object are coasting in (non-identical) earth orbits. Since the orbits are closed curves, the orbits will (forever) intersect at the point of the throw. One your-orbit-time later, you will be back at the point of the throw. One object-orbit-time later, the object will be back at the point of the throw. These times, in general, will be different and the object will not hit you. But if the "throw" is very gentle, the orbits will be similar, and after one orbit the object will be very close to you. Bob