Scott Manley did a video about this - turns out this is pretty energy intensive (asteroids are heavy & you are spinning up the whole thing) & not doable at all for many asteroid types due to insufficient material strength of the asteroid. Therefore, internal centrifuges in an asteroid cavern or spinning stations made from metal and/or advanced materials (wheels up to ONeil Island 3 design) are a much better bet than spinning asteroids.

This had me thinking - are we looking for objects in space that should not be spinning, but are spinning?

This'd at lest let us know there is life out there with the same problem, right?

I really wonder if that's part of the checklist for 'an odd object in space which we should investigate further' ..

Any artificial extrasolar objects that use spin for gravity would be far to small for current telescopes to resolve, not to mention detect their spin, if they are circular.

I'm guessing we've exhausted the search for such objects in our own solar system ..

Oh, right - tha's actually a good idea & one can measure rotation rates of asteroids: https://en.m.wikipedia.org/wiki/List_of_fast_rotators_(minor...

BTW, the recently discovered extra-solar asteroid also had quite some rotation IIRC.

I don’t think it would be too long before the aliens evolved away from the need to spin. There would be so many advantages to adapting to zero G.