Once upon a time (6:00:01 Eastern Standard, to be precise), there was a very intelligent yet highly incompetent worker at a nuclear power plant other than Homer Simpson (he was not intelligent) who caused a planetary disaster (oh all right, it didn't happen all in one second; it took two).
Fortunately for mankind, all other human beings had been transported to the galaxy Star Beam, which was not affected by the disaster. However, there was now the problem of where these billions of people would now live.
Another cause for concern was the presence of rabid wolves -- great big dudes which lived in the sewers and would peel out of there at night in hordes numbering upwards of 85, disguised as poodles. The disguises weren't very effective.
In fact, the disguises began to fall off when the wolves ran fast. As a result the billions of people knew they were wolves and ran into buildings to escape them. So the wolves starved to death.
Fortunately, our incompetent genius (we'll call him Elmo; the police wouldn't give us the real name) found the solution to both problems in one 'spill.' Elmo spilled two highly explosive liquids, and when they mixed, he knew exactly what to do!
Elmo collected as much as he could of each of the explosives and mixed them together (along with a dash of salt and a stray cat) in a giant vat. He then dropped in a match, producing the greatest explosion the Earth had ever know. In the process, the solar system was vaporised, the galaxy rose several degrees in ambient background temperature, and the planets of the Star Beam galaxy were torn apart. By a fortunate coincidence, they re-combined to form a number of human-inhabited worlds (all with great open spaces) and one rather crowded wolf-infested world with one poor cat, frightened to tears by all the poodle-ish creates around it.