This article is about a non-fiction entity related to the Astronist belief system or the Astronic tradition.
Any article relating to a fictional entity will be clearly marked as being part of the Spacefaring World.
Part of a series on
|Main attributed works|
|Omnidoxy · The Grand Centrality · The Grand Lexicon · Dictionary of Astronism · Cometanic Encyclopaedia of Astronism|
|Cometan in Astronism|
States and experiences
|Cometan in art|
|Cometan in history|
|Chronology of Cometan · Historical Cometan · Historicity · Criticism of Cometan|
|Beliefs and perspectives|
|Cometanocentrism · Removalism|
|List of Cometan website urls · List of Kometan website urls|
The 20th generation retrograde (or twentieth retrograde) is a classification of medieval ancestors in Cometanic ancestry denoting the generation of Cometan's 18th great-grandparents and their siblings. It precedes the 19th generation retrograde and succeeds the 21st generation retrograde.