Friday, July 11, 2008

The telescope


In case anyone doesn't think I'm well rounded enough, let me introduce you to my telescope, because on top of everything else, I'm kind of a science geek too. This is a 10 inch, f/6, 'dob' style telescope. You look through an eyepiece at the upper end of the tube. It uses mirrors for magnification, instead of lenses. It's considered an excellent, inexpensive way for amateurs to enjoy a high quality viewing experience. I bought the mirrors for it, but I built the rest of it by myself. In fact I built it when we lived in Yakima in 1997, and finished just in time to enjoy using it to view Comet Hale-Bopp. So this scope has been with me for 11 years! Because of health problems (I'm allergic to cold, an unfortunate condition that only developed in the last few years) I don't get to use it as much as I used to, and I have toyed with the idea of selling it, but I'm always kind of relieved when no one takes me up on it. It is the first thing I built in my workshop in our first house, and I do have many fond memories of the experience.

In 2003 Dave and I took the Airstream on our second trip to the Table Mountain Star Party (that was so much nicer than the previous trip, when we stayed in the pop top camper van). There were lots of fancy scopes there, much fancier than my little scope, but it's still fun to share it with folks who come by for a peek. Everyone peeks through everyone elses scopes at a Star Party!

People oooh and ahh over the scope for it's unique construction. Many of these big homebuilt scopes have a cardboard tube. They use a concrete form - a heavy-duty cardboard, and it certianly stands up to the mild abuse a scope gets. I decided I wanted mine to be very sturdy, and so I built it out of PVC instead. It has been to many school science fairs and sidewalk astronomy outings, and I never have to worry about anyone hurting it, it's built like a tank.

Because I drove a Geo Tracker when I built it, I needed it to break down to something more compact than it's 60 inch tube. So I put a seam in the middle, and the tube comes apart.


This is how it looked before it's most recent paint job.

I have rebuilt it several times, modifying the box it sits on and the way the tube pivots on the box. When I first built it I needed a ladder to see out of it when it was pointing straight up, but over the years I modified it until I could see out of it in any position. I also added baffles and better spotting scopes, and a fancier eyepiece focuser. I blacked out the inside of the tube with a flat black paint with sand mixed in to make it really cut down on light bouncing around in there.


So what everyone wants to know is - what can you see with it? Well, I can see the red spot on Jupiter, the ice caps on Mars, and the rings of Saturn - even the gap between the rings on a good day. And of course I can see all sorts of neat galaxies and nebula, colorful double stars and spectacular star clusters. When I used it on Comet Hale-Bopp I could see a neat corkscrew where the tail came off the head of the comet, something I never quite saw replicated in pictures.

But the big showstopper is always the moon. Here's a picture of the moon at the lowest magnification. Click on the picture to see more detail. Of course with higher magnifications it is really impressive, and you can see the Apollo moon landing sites (but no, you can't see the moon buggy or the lander or flag), and hunt down some of the landmarks you can see in the pictures. It's amazing to see a crater on the moon and know people were right there!


So after 11 years I still have my faithful old telescope. I pulled it out tonight for the first time in a couple years, and it didn't dissapoint. Later I'll get to peek at some planets through it. It really is a unique and fun instrument to have around.

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