|Characters||Guardians of the Universe Green Lantern Corps|
Oa is a fictional planet that lies at the center of the DC Comics universe. Since its inception, Oa has been the planetary citadel of the Guardians of the Universe and the headquarters of the Green Lantern Corps. It first appeared in Green Lantern (vol. 2) #1, when the Guardians summoned Hal Jordan's "energy duplicate" so they could hear of his origin.
One of the oldest planets in the universe, Oa serves as the home and headquarters for a race of blue-skinned powerful humanoids who have dubbed themselves the Guardians of the Universe. The Guardians administer the Green Lantern Corps, a group of powerful universal police officers equipped by the Guardians with green-colored power rings along with green lanterns with which to charge the rings. According to the story "Heart of a Star" in the Sandman: Endless Nights graphic novel, Oa's star is called Sto-Oa (the Light of Oa) by the children of the planet's inhabitants. Its location has been firmly established by numerous references in Green Lantern comics over the years. It was formerly the center of the universe until the events of Infinite Crisis.
Oa's history is not clear; according to some stories, the Guardians originated on a planet called Maltus. These evolved Maltusians later moved to Oa and named themselves Oans. Oa became a convenient base of operations. Other stories had the Oans living there from the beginning.
Oa appears primarily as a desert-like, lifeless planet except for the Guardians' city which contains the Corps Central Battery and various halls, living quarters, containment cells and training centers for the Green Lantern Corps. It serves basically as a planet-sized all-in-one police station, training grounds and prison.
During a period where the planet had been abandoned and the Central Battery destroyed, Oa spent some time as a patchwork mosaic of cities from other planets similar to Battleworld. This transformation was due to a rogue Guardian driven insane by solitude. When the Guardians returned to Oa, Mosaic was kept as an experiment in inter-galactic cooperative living.
Green Lantern Corps member Hal Jordan, the Green Lantern of sector 2814 (which includes Earth), under the influence of the evil entity Parallax, kills all but one of the Guardians and most of the Corps before draining Oa's Central Power Battery of its energy. During the final Zero Hour: Crisis in Time battle with Hal Jordan, Kyle Rayner destroys the planet in an attempt to defeat Hal.
In the crossover Green Lantern vs the Silver Surfer, the Marvel Universe villain Thanos attempts to use the rift created by Oa's destruction to unmake the multiverse, after tricking Kyle into powering his equipment with his ring. Thanos is confronted by Parallax and their powers are drained by Kyle and the Surfer, apparently destroying the rift. During the Circle of Fire event, what remains of the planet served as a base of operations for the villain Oblivion.
The planet is reformed sometime later by Jordan's old friend and associate Tom "Pie-Face" Kalmaku in the graphic novel Legacy: The Last Will and Testament of Hal Jordan. The Central Power Battery is later recharged and the Guardians resurrected shortly thereafter by Kyle Rayner after he spends some time as the near-omnipotent "Ion", Kyle sacrificing his power to restore the Guardians rather than risk becoming as dangerous as Hal-as-Parallax.
After attacks by Superboy-Prime and the Spider Guild, the Guardians fortify Oa by creating a planetwide armor and defensive system to prevent attacks. The full capability of the new systems is still unknown. They were not, however, enough to prevent an assault by the Sinestro Corps, which resulted in the deaths of many Green Lanterns. Afterward, the Corps doubled its defenses. However, a rogue Guardian, Scar, weakened its defenses for an attack from the Black Lantern Corps.
After Sinestro killed the Guardians for their "Third Army" plot and their part in Korugar's destruction by the First Lantern Volthoom—although he spared and exiled both Ganthet and Sayd—Hal Jordan became the new leader of the Green Lantern Corps. Shortly after this, the planet was attacked and destroyed by Relic.
The Green Lanterns' new base of operations following the destruction of Oa became Mogo.
Following the rebirth of the Guardians of the Universe and the Hal Jordan's victory over Hank Henshaw, it was revealed by Ganthet that the Guardians were rebuilding Oa in secret with the plans to restore it to what it once was, which is now referred to as "New Oa".
It is revealed in Final Crisis: Legion of 3 Worlds that Sodam Yat is the last Guardian of the Universe in the 31st century, while Rond Vidar is the last remaining Green Lantern until he is killed by Superboy-Prime's Legion of Super-Villains. Oa lies mostly in ruins, the power battery cracked, and the rings of the Corps lie in a pile, unable to locate new bearers due to the apparent death of Mogo. Statues of legendary Green Lantern Corps members, including Hal Jordan, Guy Gardner, John Stewart, Kyle Rayner, Arisia, and Ch'p, line the hall where the Guardians formerly met.
After Thomas Kalmaku used Jordan's ring to rebuild Oa, Kyle Rayner used his power as Ion to resurrect the Guardians. The book of Oa is now restored.
The Forbidden Chapter of the Book tells the prophecy of the Blackest Night, the final destruction of the Green Lantern Corps at the hands of their greatest enemies as it was told to Abin Sur by the demons of Ysmault.
Upon recruitment, a Green Lantern is expected to uphold certain principles of their duty. These principles include:
The book of Oa has been designated off-limits after being rewritten by the Guardians of the Universe to include ten new laws. Only the first four have been revealed:
When the new laws are written, the book is revealed to be written in Interlac, which is the galactic universal language used by the 30th and 31st Century United Planets and Legion of Super-Heroes.
To enforce these principles, the Guardians closely monitor the activities of the Lanterns. If they feel a violation of Corps regulations occurred, they will summon the offender to Oa and hold a trial in which the charges are read and the Lantern is allowed to explain their actions. If the Guardians are not satisfied by the explanation, they have a number of disciplinary options which include: