The August Craft, the Alien's Spaceship, was captured by the U.S. Air Force in the 1960s.
History on Earth
After it crashed and was found by the Air Force, it was put into a facility along with the Alien found inside of it. It was examined by the air force, until it disassembled, and it fell apart into the August Cubes.
In Lillian, once the alien escaped the cubes being held in the train fell out and were found by the Air Force. They placed a trap with the cubes in the town, and the alien climbed to the top of the water tower, where a magnetic force pulled several metal objects, including Joe's necklace and the cubes, onto the water tower. That reassembled the ship, and the alien flew off into deep space with it.