Atomic

 is one of the six core universes in Infinite Crisis.

Earth-17
As the Cold War was brewing between the world’s superpowers, a mysterious object from space crashed into Kansas. Mistaking the crash for a first strike, the United States unleashed its full nuclear arsenal against the Soviet Union, who retaliated. The ensuing nuclear war instantly vaporized 97% of all life Earth. The survivors hope the Earth can be healed, but the nuclear aftermath has left them with scars that never will.