What was 'Oumuamua?

 We think we actually now know what it was. And no, it wasn't a derelict alien spaceship.

Analysis of how the sun altered the object's course has allowed scientists to make a good guess as to what it was made of...

...and it was mostly made of nitrogen ice. In fact, the composition was similar to that of the surface of Pluto, indicating that 'Oumuamua may have been a fragment of a Pluto-like planet and almost certainly came from somebody else's Oort Cloud.

Which is useful and fascinating and also makes a lot of sense.

Now if we could work out where exactly it came from.