Into the Unknown: Update Special 2019

I've been writing Into the Unknown posts every month for a little over two years now, and the time feels like it's flown by. I've covered dozens of cases, and I'm pleased to say that several of them have updates, and one was solved before I published it. I have been updating the individual cases as the information has become available, but I wanted to do a big update post, so you can read through all the updates in one session.
I added a...