Analysis of information sources in references of the Wikipedia article "Fifth planet (hypothetical)" in English language version.
The "science" in science-fiction of the Gernsback period was not wholly borrowed from the outside world. Some concepts were created on a mythical level. [...] Particularly interesting is the establishment of "Bodia" (according to one cosmology of the day, a former fifth planet whose destruction formed the asteroids) as the ultimate origin of mankind and possessor of a supercivilization.
Bode's Fifth Planet, "Bodia." (A hypothetical planet between Mars and Jupiter that broke up to form the asteroid belt. It is usually fictionally considered as Earth-like, with a human population.)