On Mars, we refer to a "day" as a "sol". NASA has developed a whole vocabulary around this term, like "yestersol" and "tosol", etc.

Do any other worlds have unique terms like this? How would one refer to a day on Venus, for example, or Mercury? Is "sol" used to avoid confusion with "day", like on Mars, or is "sol" an exclusively Martian term and "day" should be used for any other world until a unique term is agreed upon?


Word are created in response to need. There are only two planets on which we have any significant presence on the surface: Earth and Mars.

When running operations on Mars, the day/night cycle is significant, so a word was needed for the length of this cycle. Especially since the sol is so close to the day, there is greater potential for confusion. Other planets either have very long rotation periods or no solid surface.

On, for example, Mercury you can use "day" until there is a need for a new term.

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