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,
Ego the Living Planet the Fantastic Four as they were off planet at the time, fighting Ego. The superpowered quartet attempted to defeat Ego by removing the power cell from one of the attached, propulsion engines, which the Thing attempts to throw into Ego's "brain". In response, an angered Ego attempts to counter with his remaining engines but, with one engine now deactivated, the other propels the now-out-of-control planet into the Sun, its gravitational pull breaking apart Ego's substance. Ego, however, slowly reforms from a few surviving particles and repairs the propulsion unit. Ego then digests a number of Dire Wraiths to replenish its