I left Kryptonopolis Prison feeling strangely... hollow. Our understanding of the Krull ship had only been partial. True, we'd learned some interesting things from our examinations, but I could not hope to reconstruct it without the original! And with Wegthor destroyed, Krypton no longer had an outer space base from which to launch giant space arks. Jax-Ur will pay dearly for his crime, for life in the Phantom Zone is not really life at all-- It is a substanceless hell! Yet even though I had brought him to justice, I felt no satisfaction-- For while he was sentenced to life, Krypton had been sentenced to death! 
- — Jor-El
World of Krypton #2 is an issue of the series World of Krypton (Volume 1) with a cover date of August, 1979. It was published on May 10, 1979.
Synopsis for "This Planet is Doomed!"
Jor-El goes on to relate succeeding events in his life: the death of his father in an accident; his discovery that Krypton was doomed to explode; his frustrating attempts to convince Krypton of its impending destruction; the creation of his space-ark in Kandor, which was stolen along with the city by Brainiac; Superman's leaving Krypton, followed by the birth of his son Kal-El; the demonstration of the Phantom Zone ray; the discovery of a Krull ship, which was subsequently destroyed during the incident in which Jax-Ur blew up an inhabited moon of Krypton; and the exiling of Jax-Ur to the Phantom Zone.
Appearing in "This Planet is Doomed!"
Featured Characters:
- Superman (Flashback and main story)
Supporting Characters:
- Jor-El I (Dies in flashback)
- Jor-El (Flashback only)
- Lara Lor-Van (Flashback only)
- Nim-El (Flashback only)
Antagonists:
Other Characters:
- Director Ven (Flashback only)
- Doctor Gaf (Flashback only)
- Doctor Mar-Ko (Single appearance) (Flashback only)
- Ice Birds
- Professor Ken-Dal (Flashback only)
- Kim-Da (Flashback only)
- The Krull (Mentioned only)
- Kryptonian Science Council (Flashback only)
- Lyla Ler-Rol (Mentioned only)
- Moliom Amn (Single appearance) (Flashback only)
- Ni-Van (Single appearance) (Flashback only)
- Nor-Kann (Flashback only)
- Rol-Nac (First appearance chronologically) (Flashback only)
- Zor-El (Mentioned only)
Locations:
- Earth
- Krypton (Flashback only)
- Antarctic
- Antarctic City
- Argo City
- Jewel Mountains
- Jewel Mountain Tower
- Kandor
- Kryptonopolis
- South Star Space Port
- Wegthor (Destroyed)
- Antarctic
Items:
- Kryptonian Robot Police
- Phantom Zone Projector (First appearance chronologically)
- Super-Robot
Vehicles:
- Brainiac's UFO
- Krull Space-Ship
- Kandorian Space Ark
Notes
- This issue is reprinted in Superman: The Many Worlds of Krypton.
Trivia
- The sky-cast vote for Molium was last seen in "Prison in the Sky" in Superman #234. Baby Kal-El's Kryptonian dedication ceremony was previously shown in "The Devil's Partner" in Action Comics #378