Classic Applied Phlebotinum found on many, many space ships in fiction. At the press of a button, a beam of light comes out of the ship and sucks in anything in its reach. Occasionally used to move things already on the ship, too. The Tractor Beam thus allows space travellers to capture enemy ships, travel to the surface of planets, and steal the farmer's cows.
Many stories with Alien Abductions [...] [tvtropes.org]