I read this short story a while back about this grey goo planet, figured one of you might have happened upon it.
- starts off with a space fleet investigating a planet
grey, completely spherical, uniform to the core in its composition
drones sent to surface disappear and are consumed
- captain of main craft realises it's the remnants of a nanite experiment gone awry
self-replication took over entire planet without a kill switch
planet obtains drone tech and with it, ballistic weapons and space travel
proceeds to destroy fleet and send infection craft to other systems
secondary craft has the last lightdrive in what remains of the fleet
- sends remaining crew and tech with it to warn the rest of the galaxy
