eyes are not sensitive enough we need to use so-called fluorescent detectors which take a movie of the sky very very fast move your disk i. o. this to physicists run channel it shows us one of the fluorescents detectives. there are four buildings like this one on the observatory site. ok we just arrived here at the fluorescent. call mostly only. if you look at this big map we are circling this point here we have three out there one is school year call which you saw on this part of the market on the west of the area the other one