Is dark matter real, or another 'Planet Vulcan'

Yes, and this is an active area of research. There was a thread from (gosh) ten years ago that touches on some of the aspects of terrestrial detection. Happy to revisit any of those points. The practical side of making measurements like these is often not given the same emphasis in pop sci as is highfalutin theoretical speculation, but the stories are just as compelling (or, often, arguably more so).