What is dark matter, the mysterious predominant constituent of all matter in the Universe? While particle dark matter has remained elusive thus far, as I will demonstrate, large dark matter experiments themselves form impressive neutrino telescopes. This opens a new window into astronomy, leading to possible insights into major problems such as the origin of supermassive black holes. As I will show, primordial black holes from the early Universe make an attractive non-particle dark matter candidate, with intimate connections to astronomical puzzles like the origin of heavy elements (gold) as well as ongoing boom in gravity wave and multi-messenger astronomy. In fact, primordial black holes from the general formation scenario of bubble multiverse might have already been seen by Subaru Hyper Suprime-Cam.