"What's the matter? All I said was that Komaytos look like little Metr—"

Non-canon warning: This article or section contains information that may not be considered an official part of the Metroid series in the overall storyline by Nintendo.


Metroid Prime 3: Corruption Preview trailers depicted blueprints for a Future Aurora Complex. While these blueprints for an Aurora Unit chamber are clearly of Galactic Federation origin, it is worthy to note that they depict a room nearly identical to the Zebesian Command Center housing Mother Brain in Super Metroid. This began a debate among fans of the Metroid series regarding the true nature of Mother Brain and the Aurora Units.


The Mother Brain present in Metroid, its remake and Super Metroid, was originally thought to be an entity of Space Pirate origin, somehow attaining leadership over the marauding race. The Metroid Manga, however, revealed the bio-mechanical lifeform seen in Metroid and Zero Mission to have been created by the mysterious Chozo race long before the events of any Metroid game. After Mother Brain is destroyed by Samus Aran in Zero Mission, the Space Pirates rebuild their leader for her reappearance in Super Metroid, as stated in Metroid Prime's instruction booklet [1].

However, weeks before the release of Metroid Prime 3: Corruption, several trailers were made available, with one of them showcasing the Aurora Units (also known as AUs), organic super-computers created by the Galactic Federation two decades before the events of Corruption. Not only did the Aurora Units resemble brains in glass containers, the trailer also featured blueprints of one of these constructs located in a chamber bearing an uncanny resemblance to Mother Brain's room in Tourian; the AU itself is placed in the exact location where Mother Brain is found in her appearances.

The images below are a side-by-side comparison of Mother Brain's first and second chambers, with the blueprints of the future Aurora complex in-between them:

Mother Brain chamber (M1).png
Mother Brain chamber (SM).png

Based on this comparison, the blueprints correspond far more to Super Metroid's chamber. Further validating this connection is the official chronology of the Metroid games themselves: the manual of the first Prime states that a group of Pirates landed on Zebes following the end of Samus' first mission in order to rebuild their fortress. The entirety of the Metroid Prime series transpire during this reconstruction, prior to the events of Super Metroid. Therefore, it is greatly implied the AU blueprints were ultimately used to rebuild Mother Brain's chamber (if not the entirety of Tourian), and possibly the Pirate leader herself, in time for Samus' second mission to Zebes.

Finally, both Mother Brain and Aurora Units are employed as computers in the manga and Corruption respectively, having access to large digital networks and processing vast amounts of information.


Due to the animosity the Galactic Federation and Space Pirates have held for each other since the former's establishment, fans were perplexed with the trailer, as the future complex and Aurora Units, clearly of Federation origin, were nearly identical to the Pirate leader in her future lair. Adding confusion to this matter was not only the manga's interpretation of Mother Brain being created by the Chozo, but also the statement that AUs were first invented 20 years ago, making it difficult to establish if the Federation's AUs came into being at the same time as Mother Brain (prior to the events of the aforementioned manga).

Numerous theories were formulated to explain the connections between the Pirate leader and the Federation super-computers. The two most popular theories are the following:

  • Mother Brain and the Aurora Units were built simultaneously as a collaboration between the Chozo and the Federation, making the Pirate leader simply a rogue Aurora Unit.
  • Mother Brain was constructed solely by the Chozo long ago, with Aurora Units coming into existence years later and being the result of Federation scientists reverse-engineering the Chozo's creation (with or without the bird-like race's consent). The pirate leader is therefore the first organic super-computer of the galaxy, mother of all future AUs, with an entirely unique AI.

Both of these theories are supported by the manga's implications that the Federation's actions, in earlier times, were influenced by the Chozo, with Mother Brain having the capacity to access the organization's database in a similar fashion to Aurora Units. Metroid Prime 3 provides further support with Aurora Unit 313 also turning rogue and gaining additional attributes parallel to Mother Brain's. There are also unused logbook entries in the same game that would have offered additional insight, such as the crew of the G.F.S. Olympus described as calling the ship's AU 242 "Other Brain", a name that their admiral disapproved due to its association with the villainous Mother Brain; this confirms that Galactic Federation personnel are clearly aware of the similarities between their AUs and the Space Pirate leader.

As for the blueprints of the future Aurora complex, there is a general consensus among fans that the Space Pirates somehow gained access to them prior, during or after the events of Corruption, using the knowledge provided to rebuild their leader's chamber, if not the entirety of Tourian, for Super Metroid, possibly through spies implanted within the Galactic Federation. This is further supported in Samus Returns where Proteus Ridley managed to not only arrive at SR388, but also ambush Samus and the baby just as they were about to leave the planet. However, it is open to interpretation as to whether the second Mother Brain is a reconstruction of the first, or a stolen AU compromised and placed on Zebes. Whichever the case is, both variants of Mother Brain are strongly suggested to possess the same personality and intellect; her identity having been transferred or copied from the first body and uploaded to the second. 


  • Another unused Logbook entry from Metroid Prime 3 states that Aurora Unit 313 was already manifesting unusually high levels of aggression long before it was captured by Space Pirates. Although its exposure to Phazon was the main factor that pushed it to its rogue, Mother Brain-like malevolence, its prior history may be interpreted as a sign that all Aurora Units carry the potential of manifesting the Pirate leader's traits.
  • The blueprints for the Aurora Complex that resembles Super Metroid's Tourian were never seen outside the trailer it was featured in. Although the Galactic Federation seemingly never put the blueprints into application, it is interesting to note that their BOTTLE SHIP's Sector Zero is stated to be a faithful replica of Tourian.

Non-canon warning: Non-canonical information ends here.

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