Space traveller venerated by the Romans (7)

I believe the answer is:

jupiter

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'space traveller' is the definition.
The definition and answer can be both people as well as being singular nouns.
Maybe there's a link between them I don't understand?

I don't understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for jupiter that I've seen before include "Largest planet in our solar system" , "A planet; Trollope's all-powerful newspaper" , "Fifth planet from sun" , "Piece of Holst" , "Heavenly body" .)

I've seen this clue in The Globe and Mail.

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