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Alright, I know that "Sol" is used on Mars to count days. But is the sun called: "Sol"? And can you use that term on Earth as well?
The reason for the question is that the term "sol" is used in two ways, but never clarified. Because it also means the sun, and the sun is what time (day/night) is based on on Earth as well as Mars. So why is Sol only used to count time on mars while it is also what time is based on on Earth? And can you use Sol to count time on Earth?
A "sol" is only commonly used for a Martian day, and it seems pretty redundant to use this term for Earth, as it is already covered by the concept 'day'. Also, it may induce ambiguity, as people think you are referring to a Martian day.
As for the other planets in the inner solar system, Mercury and Venus, they have a so long day that their orbital period may be a more useful measure of time.
Sol is simply another English word for 'the Sun', and it is also the main word for it in several other languages, including my own (Norwegian).
Some languages use the same word for 'sun' and 'day', including Maori, Hungarian and my second language, Southern Sami.
The term "sol" is short for the word "solar day", which is the amount of time it takes for mars to revolve once around its own axis. A martian sol is approximately 24 hours, 39 minutes, and 35.244 seconds.
The English word is just sun, the Spanish word for sun is sol. the french word is soleil. It would seem sort of redundant to use this term for earth, as it is already used by the concept day.
Also, Earth's days are shorter: they are approximately 23 hours, 56 minutes, and 4 seconds, which is roughly 40 minutes shorter than a day on mars. If you want more information, check out the links. I thought they were helpful :)
Some people haven't actually mentioned that sol is not the name for the sun in English. It is the name for the sun in Latin and you won't hear astronomers say "Oh, look! It's the sol!". However, sol is the name of a Martian day in English, so you will hear astronomers say "The astronauts will be there for approximately 53 sols!".
First some definitions:
Sol is short for Solar day, that is, the time it takes to get from a point on day one to the same point on day two, based on the Earth's motion relative to the sun (i.e., from the point where the sun is directly overhead one day to the sun in the same position the next day). What is usually used is the average over time, as the length of a solar day can vary (and does, on Earth and Mars, due to axial tilt and elliptical orbits). One mean solar day is 24 hours on Eath, and 24 hours, 39 minutes, 35.2 seconds on Mars.
A Sidereal day, on the other hand, is the time it takes to get from a point on day one to the same point on day two, based on the Earth's motion relative to the stars. It is the time it takes a planet to rotate completely around its axis. It likewise varies. One mean sidereal day on Earth is 23 hours, 56 minutes, 4.1 seconds; on Mars is 24 hours, 37 minutes, 22 seconds.
Sol is the Latin name for the sun (and some other languages derived from Latin), but context should quickly distinguish the two meanings; I can think of no examples (that are not needlessly convoluted) where the two could be mixed up in usage.
The shorter 'Sol' could also be used for the solar days of other planets rather than the full 'Solar day', but is not likely to be, just to avoid confusion. (Mars got dibs on that one!) It might be used with the name of the planet or moon to sufficiently distinguish it. So far the issue hasn't come up, as there is rarely need to reference the length of days on other planets. It only arose with Mars because of the rovers and probes that have been sent there that operate on solar power, making it more convenient for the people who worked with them to operate on the same solar schedule that Mars does. Humans being humans, "Solar day" got shortened to "Sol", and after enough use that became the recognized word for a solar day on Mars (and 'yestersol' as the solar day prior to the current Sol).
