Tag Archives: telescope

Chilbolton Radio Telescope

A couple of years ago, I was taking a road trip across the Cascades and I came upon a large dish alongside the road.  It was a surprise and ended up being a blog post.  I guess it is a little less spontaneous to search out a dish but, while I was over at Middle Wallop, meeting up with my friend Paul, I knew I was near the old airfield at Chilbolton.  This had been an RAF base and then was used for test flying by Supermarine and Folland.  What I didn’t know until I looked it up was that the airfield was taken over for use as a radio telescope after it closed to flight operations.  I decided to swing by and see the dish.  As I came over the hill, I could see it in the valley but the road was narrow and there was nowhere to stop.  I got to the gate and a big sign advertised that random visitors were not welcome so I had to make do with a shot from the gate.

Listening to Space

After leaving Brewster on my road trip, I was heading a short distance to the next town of Monse.  A short unpaved road would take me there but along this road was something I had not expected.  A bloody great deep space antenna was right next to the road.  As I pulled up alongside it, there was a sign announcing that is was part of a large array of receivers around the world.  The sign outside also asked you to turn off your cellphone if you entered since the signals could interfere with their reception.  If I had known it was there and that you might be able to visit, I might have planned a stop but I had a full schedule ahead of me so I briefly paused before moving on.

Up on the hill behind the receiver was quite an array of antennas.  A look on Google Maps suggests it is part of a cable company’s operation but it does look a little more complex than that.  Maybe it does some secret squirrel stuff or maybe I am letting my imagination run away with me!

The Old 36 Inch Refractor

AU0E3395-Pano-Edit.jpgIn the days before reflecting telescopes, refractors were used. In order to see further and further they got larger and larger. This meant very long telescopes and making these was technically very difficult. The reflecting scopes removed the length limitations and introduced far larger apertures in a manageable size. The old refractors were overtaken. However, they are still very usable. The 36 inch refractor at the Lick Observatory is still in regular use. They do provide tours of it for visitors.

AU0E3421.jpgThe building it is housed in is quite grand in itself. A function of its time, it has a wonderful wooden floor that is designed to be raised and lowered to allow the observer to reach the end of the telescope irrespective of what angle it is pointing at. The floor movement is current not in use and they have a sturdy ladder instead. The telescope itself is quite huge and it is amazing to think how long it has been in use.

AU0E3381.jpgThe tour was very interesting and the guide really had a passion for the scope and the work they do with it. He also allowed me to get some additional shots once everyone had moved on which was very kind.



Shane 3m Reflector

AU0E3325.jpgIf you know your optical telescopes, you know there are two main types – refractors and reflectors. Refractors use lenses to magnify the image and reflectors use mirrors. Reflectors can be much larger and gather more light so took over from the traditional telescopes. At the Lick Observatory, they have the Shane 3m Reflector. (For those who can’t use sensible units, 3 metres is 10 feet.) the building that houses the telescope has a visitors gallery. You aren’t in the room with the telescope but you can see into the space that houses it.

AU0E3337.jpgThere are a number of display screens showing how it works and how it was constructed. The clever stuff is out of sight and the main structure is all about holding the mirrors in the right place and reorienting them when required to track a subject. The structures are some substantial bits of steel and getting them up the mountain was no small feat. Nothing was in use while we were there (during the day!) so you had to imagine this large structure being moved around to track the next celestial body. Given that the building has to be at ambient temperature to avoid any heat distortion when I use, I think I was quite glad it wasn’t working since it was a cold and snowy day up on the mountain.