From Bulbapedia, the community-driven Pokémon encyclopedia.
Ultra Space (Japanese: ウルトラスペース Ultra Space) is the home of Ultra Beasts, accessible via Ultra Wormhole. Professor Burnet is researching these strange phenomena.
Ultra Space is an interdimensional spatial realm filled with crystalline meteoroids and populated by Necrozma and multiple instances of members of the Cosmog line. It links to a number of different universes and dimensions through Ultra Wormholes - while they may naturally occur, they are more commonly deliberately opened up by Solgaleo, Lunala, and Necrozma.
In ancient times, Necrozma's light shone through the Ultra Wormholes connecting to various worlds such as the Ultra Beasts' homeworlds, Ultra Megalopolis, and the Pokémon world, primarily over the Alola region. However, following an incident with the residents of Ultra Megalopolis years ago, Necrozma's body was damaged and it lost the ability to produce light, the agony caused by its injuries sending it into a berserk state where it constantly hungered for light. As a result, it was imprisoned in Megalo Tower. Kukui theorizes that the Sparkling Stones found across Alola and fashioned into Z-Power Rings are the lost pieces of Necrozma's body.
At one point in the past, a SolgaleoSUS/LunalaMUM arrived in Alola from Ultra Space and won a fight against the guardian deities. Solgaleo/Lunala bestowed the Tapunium Z to the guardian deities, and in conjunction with a LunalaSUS/SolgaleoMUM produced several Cosmog that were revered by the region's monarchies and protected by the four tapu, before the Legendary Pokémon departed back to Ultra Space.
At another point in the past, Necrozma appeared in Alola and stole its light, covering the region in darkness. Necrozma clashed against the guardian deities, who fought to defend Alola. During that time, Necrozma also absorbed SolgaleoUS/LunalaUM to become its Dusk ManeUS/Dawn WingsUM form. With the assistance of a youth, Z-Crystals and Sparkling Stones, the deities banished Necrozma, freed SolgaleoUS/LunalaUM, and reclaimed Alola's light.
In the games
Pokémon Sun and Moon
The player is only able to visit the home of Nihilego, Ultra Deep Sea (referred to as Ultra Space), in order to save Guzma and Lusamine from an Ultra Wormhole at the Altar of the SunneS/Altar of the MooneM.
Pokémon Ultra Sun and Ultra Moon
The following areas can be accessed by merely interacting with the Ultra Wormhole at the Altar of the SunneUS/Altar of the MooneUM:
Unlike in Sun and Moon, the player can travel through the Ultra Wormhole with Solgaleo or Lunala using Ultra Warp Ride and access several new Ultra Space areas. The following areas can be accessed this way:
If a Pikachu, Cubone or Exeggcute is evolved in Ultra Space, it would instead evolve into Raichu, Marowak or Exeggutor's original Kanto form instead of their Alolan form
In the TCG
This listing is of cards mentioning or featuring Ultra Space in the Pokémon Trading Card Game.
In other languages