Bowser's Dark Matter Plant is a galaxy featured in Super Mario Galaxy. It is the boss galaxy of the fourth world, which is accessible from the Comet Observatory's Bedroom. As its name suggests, Dark Matter is prevalent as the galaxy's prime enemy.

Mario can access this galaxy if he has 33 Power Stars in his possession, including the Grand Stars from Bowser Jr.'s Robot Reactor, Bowser's Star Reactor, and Bowser Jr.'s Airship Armada.


There is only one mission in this galaxy: Darkness on the Horizon. Here, Mario has to get to the centre of the reactor, where King Bowser Koopa awaits...

Names in Other Languages

  • Japanese: Kuppa Dāku Matā Puranto (Bowser's Dark Matter Plant. If the galaxy's name were translated properly, we would have gotten Bowser's Dark Matter Reactor.)
  • Spanish: La dimensión Kupe Matériad Oscúrad (Bowser's Dark Matter Dimension)
  • French: La Usine de Matèrie Noire de Bowser (Bowser's Dark Matter Factory)
  • Portuguese: La Dimensão Kúpai de Materia Oscura (Bowser's Dimension of Dark Matter)
  • Italian: La Dimensione Kupe di Materia Oscura (Bowser's Dimension of Dark Matter)
  • Latin: Dimensiō Kūpae Materiā Obscūrā (Bowser's Dimension of Dark Matter)
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