Turbo Jones predicted the destruction of Earth by a vast meteor shower and set about building the spaceship Wildcat with the help of his three chosen 'second-in-command' - Loner, Kitten Magee and Joe Alien. With their help (and finance), the ship is built in three years and blasts off in to space, searching for a new home for the Earth orphans.
Joe Alien is a story from Wildcat comic that continued in Eagle, when the two comics merged. Joe's story restarted in Eagle issue 372 (after the first Kitten Magee story had run in issues 368-371).
The last Joe Alien story appeared in Eagle issue 392.