Earth-like world with 18 hour day

Given a "parallel" Earth-like world with 9 days to our own 7 days (ie, each day is around 18 hours, 40 minutes), what other differences would one expect/require to be otherwise "normal" and habitable?

Would such a world necessarily need to be of different diameter, mass, orbital distance, etc? Or could one assert that everything else is completely Earth-like?

One other exception I had in mind was having dual, larger moons with inherently more varied tidal patterns, as well, but I'm unsure if I'm overlooking something about how the length of a day might influence seasons, water cycles, or imply something like a greater or lesser year length or orbital distance.

PS. Safe to assume native species will have suitable adaptations, ie, not transplanted Earth life that would have to adapt.

posted over 8 years ago

BRPocock‭

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