Fictional planets of the Solar System a "tenth planet". Since 1992, a very large number of objects have been found beyond Neptune; all the objects in the following list, however, are purely fictional. Common names for trans-Neptunian planets in fiction include Planet X, after a planet once believed to lie beyond Neptune, and Persephone (or Proserpina), after the wife of Pluto. Rogue planets in fiction usually originate outside the Solar System, but their erratic paths lead them to within detectable range of Earth. In reality, no rogue planet has ever been detected transiting the Solar System. Fictional planets of the Solar System The fictional portrayal of
Promethei Terra Promethei Terra Promethei Terra is a large Martian region covering 3300 km at its broadest extent. It lies to the east of the massive Hellas basin. Like much of the southern part of the planet it is a heavily cratered, highland region. Promethei Terra was named for a classic albedo feature of Mars, with the original name derived from that of the Greek god Prometheus. Promethei Terra lies mostly in the Hellas quadrangle of Mars. One very important feature common in Promethei Terra are piles of material surrounding cliffs. These materials are called lobate debris aprons (LDAs). Recently, research with