There's a new BBC article about colliding globs of plasma shot out of a supermassive black hole which is kind of fun—Hubble spotted this over the span of 20 years, and it was able to see this happening at the center of galaxy NGC 3862, 260 million light years away, because the supermassive black hole propelled the plasma up to 98% of the speed of light!
Listening to free audiobook recordings of the Sherlock Holmes short stories got me on the path of this amazing and extremely rough : p coincidence in common or once common systems of measurement: a league is to a mile as a parsec is to a light year as the circumference is to the diameter. Right? Sorta? Spoooky.