[krames]

I understand that pretty much everything from comets, planets and our own weather that everything tends to gravitate with an east west or west east movement. I get the idea of how an object in orbit gravitates around the planet but that is with a west east kind of movement. If an object is orbitting earth and has a north south orbit would it not need propulsion to continuosly push this object to match the speed of earth as it goes around it? If an object is propelled would it not be considered flying instead of orbitting? Wouldn't an object in a north south or south north, however you want to look at it, orbit would then be moving in more of a corckscrew path to maintain a straight line?

[ebaines]

It's certainly possible to have a north-south orbit - meaning that the satellite passes over the north and south pole each orbit. For such a satellite that orbits every 90 minutes (similar orbital period as the international space station) the earth rotates under it by about 25 degrees or so for each orbit. Observers on the ground would see the craft having a slight east-west drift as it passes overhead, deviating from true north-south by just 3 or 4 degrees.

It would not be possible to have an absolutely true north-south orbit as observed by someone on the surface of the earth without some form of propulsion to make it steer east-west as it orbits.