The Rao System is the planetary system that is home to the planet Krypton, throughout the various continuities and versions the system has varied significantly.
The amount of planets and celestial bodies varies greatly throughout different continuities, realities, and timelines. Post "Crisis on Infinite Earths" the planetary system was established as having five planets within it.
- Rao - Central body of the system, consistently portrayed as a red star.
- Boron - is the smallest and innermost planet in the Rao System. Its orbital period around the Rao is the shortest.
- Phalon - is the second planet from Rao.
- Thalon - is the third planet from Rao.
- Krypton - Consistently habitable world portrayed in every version of the planetary system, home planet of the Kryptonians. Said to be the fourth planet from Rao in the "Earth-1" universe (post infinite crisis).
- Agoron - One of Kryptons two moons post-flashpoint (new 52), home to one of the most inhospitable environments in the system, but it appears to have native vegetation.
- Wegthor - Moon orbiting krypton in most continuities, in virtually all continuities the moon was destroyed by Jax-Ur. The moon during its destruction apparently had a kryptonian colony on it.
- Koron - Often said to be the largest (or larger) of kryptons moons, in one continuity it was stated that Jax-ur had destroyed this moon rather than Wegthorn.
- Xenon - In some continuities this moon spun out of orbit and was lost before the destruction of Krypton.
- Mithen -
- Argo - A moon exclusive to the comic series Supergirl: Cosmic Adventures in the 8th Grade it is home to a colony of Kryptonians.
- Haron - is the fifth planet from Rao.
- Dheron - A planet found within "Earth-1" universe (post infinite crisis), is the fifth planet from Rao and is a habitable world with similar aspects to krypton, as well it has its own humanoid race the Dheronians.
- Thoron - A planet inhabited by a race of humanoid peoples resembling humans and kryptonians in many ways having much of the same abilities as Kryptonians. The planet was introduced in Superman #80 (v1) and has no known other appearances.
- Imitation Krypton - A planet created by the kryptonians to emulate krypton in every way imaginable in order to thwart extra-solar space raiders. This planet is exclusive to pre-crisis mainstream continuity.
- Imitation Krypton 2 - Another planet created by the Kryptonians to thwart extra-solar invaders, this one inhabited by android duplicates of the population and filled with booby traps, was given its own artificial sun to orbit so its unknown how long this planet was in the system. This planet appears exclusive to pre-crisis mainstream continuity.
The location of the solar/planetary system has varied dramatically from continuity to continuity. Sometimes the system is as few as 20 light years distance from earth, and other times in completely different galaxies. Every location will be listed here with the source material to avoid confusion as much as possible.
- Atlas of the DC Universe - The red sun krypton orbits is located 50 light years away from the earth.
- In Superman: Birthright - Krypton is a megagravity planet circling an M3 star in the Andromeda Galaxy.
- "Star Light, Star Bright..." - Neil Degrasse Tyson identifies Krypton as orbiting the star LHS 2520, 27 light years from Earth.
In other media
Argo - Typically Argo in most continuities is a city on Krypton, in Superman: The Animated Series (and accompanying DCAU tie-ins) it is a planet seemingly within the same orbit of krypton on the opposite side of Rao (the Superman Adventures comics state it is the fourth planet from the sun). It is inhabited by a humanoid people called the Argoans who are largely identical to Kryptonians.
- Blue Moon - Mentioned in the Superman Adventures comic as a moon of Argo.
In Superman Returns, a sequence in which Superman journeys to his home planet was cut from the film. When he reaches the former location of Krypton, all he finds is debris. A number of concept pieces were developed for the scene, and some footage was shot.