Annwn Regio
region on Europa
Annwn Regio is an extensive, relatively dark surface feature on Jupiter's fourth largest moon Europa. It is an irregular feature dominated by several crisscrossing lineae (or line terrain).
Naming
Annwn Regio is named after the Otherworld in Welsh mythology. According to the most widely accepted version of Welsh mythology, Annwn is the land of the gods and souls of the blessed dead, a place where there are no suffering or diseases, and where food and alcohol are always abundant.
The International Astronomical Union (IAU) chose this name following the rule that surface features on Europa should be named after figures and places associated with either Celtic mythology or the Phoenician princess Europa from whom the moon was named after. Annwn is a spiritual place derived from Welsh mythology, and Welsh mythology is part of the broader Celtic mythology. The name for Annwn Regio was approved by the IAU in May 2007.
Location
Annwn Regio is a massive, relatively dark region occupying much of the trailing hemisphere of Europa.
To the northeast of Annwn Regio is the extensive bright region called Falga Regio, while to the east is another dark region crater called Dryfed Regio. To the southeast the prominent ray crater Pwyll is situated, while to the south is the multi-ring structure Callanish.
This brief starts where responsible research should: with the source description of “Annwn Regio” as region on Europa. Everything that follows is an evidence route, not borrowed authority.
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The subject matters to the general reference register because the source frames it as region on Europa. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Aug 31, 2026. The linked authority identifier is Q25909111. Authority coordinates are 20.000, -320.000. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 2007.
The absence of detail may reflect summary conventions rather than a lack of surviving documentation. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
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This entry incorporates text from “Annwn Regio” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.