Publication history of Superman written by Alan Moore with art by Curt Swan. Although the new Modern Age version of Superman is said to have already been active for many years, most previous Superman appearances and elements were rendered out of continuity by John Byrne's "The Man of Steel". Later stories such as "" bring many of the Silver Age elements back into continuity. In Byrne's version, Superman came from the planet Krypton which was re-imagined as a cold, sterile world in deep contrast to the wonderworld of the past 48 years. Once Kal-El's rocketship (containing genetic materials and a birthing-matrix which resulted in
Mongo (fictional planet) the air, which caused acid rain, killed wildlife, and contaminated Mongo's water. The planet became uninhabitable. A small portion of Mongo's people emigrated to Arkaylia. After three generations on the artificial moon, Mongo's environment partially repaired itself. As a result, the people returned to the planet. Clean water, known as "source water", still remained scarce and came from underground. Centuries later, Ming seized power and began his rule. The 1977 Fantasy Games Unlimited role-playing game "Flash Gordon & the Warriors of Mongo" used the planet Mongo as its setting. The game was designed by science fiction writer Lin Carter and