I was working on a book project about California history and traveling between locations in Northern California. I've always been an armchair astronomy and cosmology buff, so when by chance I whizzed by the sign that said something like UC Hat Creek Radio Observatory (HRCO) at 55 MPH, I knew immediately what it was. I made a quick U-Turn and followed the signs to the entrance to the Observatory. I was delighted to see that the public was welcomed to take self-guided tours on limited daytime hours M-F, or by special arrangement.