In 2372, Ensign Harry Kim experienced an accident involving a time stream while running a polaron scan using the shuttlecraft Drake. Later, when recreating the accident in an alternate timeline while aboard the USS Yellowstone, he again ran a polaron scan. (VOY: "Non Sequitur") Borg cubes possessed polaron beams, capable of scanning through Federation shield technology. In 2373, one such cube momentarily stopped to scan the USS Voyager during the pursuit of a Species 8472 bio-ship. (VOY: "Scorpion")