A Galactic Tracking Device was a device invented by the Martians, shortly after the discovery that communication could go faster than the Speed of Light (6432AD). Once placed on a target the user wishes to track, it can keep transmitting up to date co-ordinates to the reciever for centuries, which is the main reason it was used on the Jah Bar non-entity. This same technology was used for centuries after the end of Solar War One.