Its finally come out from NASA, we do have UFO's orbiting different planets including our own.

Watch these you tube vids.  Its pretty revealing.

http://www.youtube.com/watch?v=RO5cb-BIy3M&feature=related

http://www.youtube.com/watch?feature=player_embedded&v=tS3dDdXVs8k

http://www.youtube.com/watch?v=6X96xI1gLdQ