Rocky planets could be triaxial spheroids. But so far the largest known is I think Haumea, a dwarf planet in form of a triaxial spheroid dimensions 1,920 × 1,540 × 990 km
Theoretically, a rapidly rotating planet could have two or three, or even more lobes joined together in a "Rocheworld" type arrangement. Or could even be donut shaped.
And they could be rounded triangles or rounded squares or rounded pentagons in cross section also.
But no such have yet been discovered.
For more about that:
So You Thought You Knew What Planets Look Like? ... Shapes Of Rapidly Spinning Planets
But no such have yet been discovered.
For more about that:
So You Thought You Knew What Planets Look Like? ... Shapes Of Rapidly Spinning Planets
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Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
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