Very big news: A comet discovered just a couple of weeks ago appears to be one the most rare and exciting of all cosmic beasts: An interstellar visitor — literally an object coming from interstellar space, from an alien star!
The object is called C/2019 Q4 (Borisov) — though that name may change, as I'll get to in a sec — and it was discovered in observations taken on August 30, 2019 at the Crimean Astrophysical Observatory by Gennady Borisov using a custom 0.65-meter telescope. It didn't take long to find the object had an, um, unusual orbit, and follow-up observations taken a few days later using a much larger telescope confirmed its strange nature. There have now been quite a few observations, and although many mysteries remain, we can be pretty sure this thing came from Out There.
To be probably too careful here, I want to say that there is a slim chance it's not from outside our solar system, but honestly at this point I wouldn’t put much money on that. As more observations come in it looks more and more like this is the real deal.
An image of the possible interstellar comet C/2019 Q4 taken ...