I asked for a brief description and failed to give a brief description of Bitcoin Astronomy lol. Sorry, here you go: It's about a future where we colonize mars and bring bitcoin with us. It rationalizes that it's impossible to mine bitcoin from mars because of the limitations of the speed of light based on our distance from Earth's "Center of Hash" (defined in the article). However, we would still be able to use bitcoin on mars, but transaction settlement would just be delayed a bit. The article then goes on to the idea of creating another Bitcoin in other solar systems. It's really fascinating to read about!