Trillions of Rogue Planets Could Be Careening Through Our Galaxy

I've been reading science fiction for a long time, and we never thought this before.

Trillions of Rogue Planets Could Be Careening Through Our Galaxy

Oh sure we have; that's one of the theories for the missing "dark matter" that astrophysical calculations predict.

But the problem with this theory is the transparency of the night sky.  If trillions or quadrillions of cold bodies inhabited the sky we'd expect more occlusion of starlight.