Sonnenborgh Observatory

Saturday night after visiting the Utrecht Univeristy Museum, we climbed to the top of the Sonnenborgh Observatory. Our guide had built some Galilean modeled telescopes. These scopes, though made of PVC pipe, allowed the user to see a distant object by the use of a concave and convex lense system. The objective lense, which was the convex lense, had a focal length of about a meter. The eyepiece lense, or concave lense, had a much smaller focal length of merely millimeters. This system of lense cause the image to be non-inverted and magnified. Since there was cloud coverage for most of our viewing time, we viewed some neon signs in the distance. Finding objects with these telescopes was much harder than one would imagine. It really put it into perspective that since you need to know what you are looking for before use, Galileo must have had a frustratingly difficult time. The second set up, a Kepler telescope, was a system of 2 concave lenses with the objective lense having a larger focal length (4 meters). The eyepiece lense had a focal length similar to that of the Gallilean eyepieces. This system creates an inverted but magnified image which we saw with the neon signs being upside down. This set up was challenging to find the object since you had to move the lens in the opposite direction you would expect, due to the inversion. It was amazing to be able to see the way Galileo did. Before leaving, we all got a chance to look through the observatory's main telescope (from 1854). It was an amazing experience all together!