Fifth planet (hypothetical) into the Sun. Unlike the Disruption Theory's fifth planet, "Planet V" is not credited with creating the asteroid belt. The concept of a fifth planet which had been destroyed to make the asteroid belt, as in the Disruption Theory, has been a popular one in fiction. Fifth planet (hypothetical) In the history of astronomy, a handful of Solar System bodies have been counted as the fifth planet from the Sun. Under the present definition of a planet, Jupiter is counted as the fifth. There are three main ideas regarding hypothetical planets between Mars and Jupiter. During the early 19th century,
The Magic School Bus Lost in the Solar System the book. Most notably, in the episode, Janet's bragging about herself does not appear to be empty bragging and she constantly raves about how "proof" is needed for all extraordinary claims, prompting her to force Arnold to collect "proof" from every planet in the solar system, so she can prove to the students in her class that she actually traveled to all the planets. Also in this one Arnold surprisingly suggests going to outer space himself to prove to Janet the truth. Also, instead of remaining in the asteroid belt, Ms. Frizzle uses her jet pack to fly off to