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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

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The Vendox, the primary symbol of Astronism.

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Existences of the Astronic cosmology
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Sideria, often stylised as the Sideria, is the Astronist eschatological event involving the closure of humanity's scope window for transcension. The Sideria is often narrated as being part of a broader series of end-time or near-end time events in Astronism that centre on the endeavour of transcension and humanity's successful fulfilment or failure to fulfil this endeavour.

The prospective occurrence of the Sideria is significant because it marks the end of humanity's opportunities for placement in order to achieve degrees of the subsequent transcension. The degree to which this closure is absolute in its consequences for scope continues to be debated. Also, a plethora of views exist as to the nature of the Sideria, namely when it will occur and what signs will emerge to demonstrate either its occurrence or its impending occurrence.

Whatever the school of thought consists of as to its views on the Sideria, Astronist orthodoxy asserts that the Sideria is inevitable to occur regardless of whether humanity has achieved or embarked upon its achievement of transcension or not.

The Sideria is most often intertwined with the conception of humanity as remaining a monoplanetary species yet the Sideria is regarded to occur to humanity whether humanity becomes multiplanetary or multisystemic. One of the primary purposes of the endeavour of transcension is to delay the occurrence of the Sideria in order to then delay humanity's inevitable devolution.


  • Siderial (adjective) – relating to the Sideria.
  • Siderially (adverb) – in a way characteristic of the Sideria.

See also