Oumuamua Is Weirder Still
It was weird enough that Oumuamua suddenly appeared from well out of the plane of the Solar System on a hyperbolic path, a dark cigar shaped object rotating end-over-end.
Now it has been observed to be accelerating (changing direction) which would appear to require a non-gravitational force.
Scientists have concluded that Oumuamua is a comet and that the non-gravitational force is due to the oft-observed outgassing that comets do when heated by the Sun.
However, Oumuamua certainly does not look like a comet, and to my knowledge no outgassing has actually been observed. Previously I have never seen convincing evidence extraterrestrial visitation. However, Oumuamua fits my imaginary idea of what an advanced civilization might do if it wanted to covertly check out other stellar systems: a robot probe disguised as a natural object and moving from one star system, to the next, and the next, …
I believe Arthur C. Clarke wrote a sci-fi novel called Rendezvous With Rama that has one thing similar to the Oumuamua case. Rama was an alien ship that was first identified as an asteroid in 2131 coming in from out beyond Jupiter.
I believe I read that scientists did look for electromagnetic signals coming from Oumuamua, but observed none. Probably Oumuamua is a natural object, rather than an artificial one. But it sure has been fun watching related developments and letting the imagination have a little free rein for a while.