Over the course of multiple episodes, it's revealed that this town is not "the" town that the teens grew up in, just a very convincing lookalike. The stars above New Ham are different, and certain celestial events, like the eclipse that occurs during the first part of the series, would not have happened on their original Earth. It's concluded that New Ham is a parallel universe to West Ham, one without any adults — but why it exists, and why everyone is here, is never really discovered.