In 1962, astronomers found an object so bizarre they had *no idea* what it could be. When they figured it out through a clever trick of the sky, they opened up a new field of science... and the Universe. https://www.syfy.com/syfywire/most-distant-astronomical-object-ever-seen-in-1962

2/ I won't give away the story, since I think it's such a fun and interesting one, but please note the update after the foreword of the article. There's more to this than I knew even after doing quite a bit of research before writing it. Thanks to @AaronJBarth for the tip!

3/ And I find it funny that I spent weeks working on that chapter of my book, didn't use the story, let it sat on my drive for 12 years, finally wrote it up earlier this year, finally posted it months later... and then within a couple of hours I find out part of it is wrong. :)

4/ SCIENCE!

5/ Side story: Back when I worked on Hubble, I was briefly involved with a project to look for an extremely distant source of light in the Universe (details are complicated and too much for Twitter). It was at a redshift of z=7, farther than anything seen at that time IIRC.