Every Saturday and Sunday, the Visitor Information Station at the Onizuka Center for International Astronomy on Mauna Kea offers free guided summit tours. There are, of course, some restrictions for liability purposes - you can't go if you're under 16, pregnant, have a history of heart or respiratory problems, have been scuba-diving in the last 24 hours, or have failed to bring a vehicle with 4 wheel drive and low-range gearing (unless you can talk someone who brought one into giving you a ride, of course). So, obviously, scuba-diving pregnant teens with heart problems and sports cars are right out. Folks show up at the Visitor Information Station, watch the "First Light" video about the mountain (which debuted on PBS Hawaii in June), then we all caravan up with a ranger along for safety, tell them about the mountain, the geology, Hawaiian history, culture and religion, and oh, yeah, the telescopes. And, we actually go into two of the observatories, wh