A transwarp signature was a detectable energy phenomenon created by the use of the transwarp conduits utilized by the Borg. In 2373, when it became apparent that they were approaching Borg space, Harry Kim, operations officer on the USS Voyager, configured the ship's long-range sensors to scan for transwarp signatures, so as to provide an early warning system for the approach of Borg vessels. A short time later, Kim detected such signatures when fifteen Borg cubes approached the Voyager. (VOY: "Scorpion")