Greetings from Palmia Observatory
Well, the latest Mars rover is now on its way to Mars. When we look up in the night sky and see Mars and wonder what will be found, we note that Jupiter appears also nearby, but of course it is much further away.
Here is a DSLR image of Mars and Jupiter using a 110 mm lens focal length setting so that both planets fit in the same view.
Many astroimagers take a lot of images of Mars and Jupiter and get pretty spectacular images of the surface features by removing the effects of atmospheric seeing and by stacking many images together. That is too much work for me, but I do like to put a little more magnification on Jupiter and look at the current location of some of the brighter moons. In this image, Jupiter is overexposed and three moons are easily visible and the 4th moons is just barely visible. By measurement, the distance from first moon to last moon is about 14 arc minutes.
As many of you know, when we bump into each other out at various meetings and observing star parties and I get asked about what scope I use I usually tell them that "I started with an eight inch scope and found that kind of heavy to set up so traded it in for a five inch scope and then got tired to lugging that around so traded that in for a three inch scope and if I continued on this journey I probably would end up with a scope as small as Galileo's!" Well, part of that story is true, I still have the 3 inch scope and actually ordered a scope called the "Galileoscope" because it is about the same size as that used by Galileo.
So, I'm not sure as to the details about how close it matches one of Galileo's early telescope other than it has a 2-inch objective lens. I purchased it as a kit from "My Science Shop" during the early phases of our pandemic lockdown and thought it might be fun to assemble it and take it out for a test drive. Well, after sitting on my desk for months, I finally decided to put the kit together. This is what the assembled scope looks like.
|Assembled version of the 2-inch Galileoscope (Source: Palmia Observatory)|
Now the telescope arrives in the mail as a kit and you have to assemble all of the parts yourself. Here you can see what the parts list and instructions look like. Luckily there are a few more pages of how o assemble the parts.
|Assembly instructions for the Galileoscope (Source: Explore Scientific)|
One of the more difficult tasks was the assembly of the multiple lenses used to make up the eyepiece. The 2-inch object lens was easy to install, but the little 17 mm diameter eyepiece lens came as four separate lenses. Two of the lenses were flat on one side and concave on the other, while the other two lenses were convex on each side. Hmm, for me it was kind of hard to see the difference and hold and assemble the lenses correctly without getting my big thumbs and fingers all over the important surfaces.
So, after about of hour of work, and a couple of hours just working out if the eyepiece lenses were assembled correctly, it was time to put the telescope into action. The kit comes with one set of lenses good for 25 x power and another for 17 x power. I used the 25 x power eyepiece and now it was easy just pointing the scope out the office window and looking for some remote object. In this image you can see an (inverted) image of a distant red fire water fixture. This image was taken after focusing the Galileoscope, by sliding in and out the eyepiece assembly and then using the iPhone to capture the image from the eyepiece.
|First light through the Galileoscope with iPhone imaging at eyepiece (Source: Palmia Observatory)|
So, the image seems to be inverted vertically and also mirror imaged, right to left. This difference is apparent once we compare the image from the Galileoscope with one from a modern DSLR. The image below was taken from the same location with a 300 mm lens.
The DSLR image has a horizontal field of view of about 4.75 degrees. After comparing the different pixel measurements from the two images, it seems the field of view of the Galileoscope is about 1.3 degrees, which translates to about an equivalent DSLR 1050 mm lens focal length.
So, everything looks ok and the scope is ready for its first nighttime use and the selected target was to look at Jupiter and see what could be made out about the moons in orbit around it. Again, I was just going to use my iPhone camera and take a picture of the image that showed up in the eyepiece. It worked fine in the office, but now outside, at dark, and mounted on my flimsy tripod, it was just not going to work. Each time, I tried to adjust the focus, the whole assembly wobbled around and didn't return to the exact point it was pointing. By the way, trying to point a telescope with a 1 degree field of view was not easy for me, who had not looked through an eyepiece for several years now. Also without a right angle mirror so you don't have to look straight into the eyepiece, I found it very tiring to operate the scope. So, it was time to get the heavier tripod out and use it for the first use of the Galileoscope. You can tell you are in a city lights polluted location when you can see a shadow cast by your equipment.
|Outside with Galileoscope and bright city lights (Source: Palmia Observatory)|
I found that my best chance of finding Jupiter in the eyepiece was with the scope a bit out of focus. That way, since Jupiter is so bright, I could see like a big fuzzy ball of light when I was getting close to getting it in the field of view. Then trying to focus and position my iPhone next to the eyepiece was the next challenge. This next photo shows the first attempt. It initially looked like it was sort of in focus, but when I pushed the iPhone shutter release, all I got was this photo below. Hmm, at least there is a fuzzy ball of light in there!
Wow, this is getting hard and I am not used to looking through an eyepiece and the target, Jupiter, is really whizzing across the sky as the Earth rotates in this 1050 mm focal length lens equivalent scope. So, I'm down on my knees so I can look into the eyepiece and still point towards Jupiter. Then make sure the focus is set properly and then try to position the iPhone camera next to the eyepiece lens and then finally snap the shutter release. Next time maybe I'll bring out the lightweight tracking mount, so I could concentrate more on getting the camera lens next to the eyepiece. I was pretty exhausted by the time I snapped this photo, which was my best and last photo of the evening. The photo even has an errant house lamp that reflected its way into the scene.
|Final attempt at getting iPhone image of Jupiter with Galileoscope (Source: Palmia Observatory)|
The next evening the crescent moon was up and low in the sky, which meant I didn't have to get down on my knees to see it, so I made another iPhone camera capture through the Galileoscope eyepiece. Yep, the crescent moon shows up it seems I'm getting a lot of background light from clouds or city lights leaking in, reflecting off the lens into the camera. I guess with more practice I could get the iPhone camera closer to the eyepiece or better yet use a camera clamp to keep it in place. I have a clamp designed to do exactly that if only I could find which drawer or cabinet that little used piece of equipment was hiding. Nope, not going to look for the clamp. I'm just too lazy to fiddle with Galieoscope or look through an eyepiece anymore. At the same time, it seems that with a scope of that size, Galileo could indeed make out details of the lunar surface and track the moons of Jupiter. But the Galileoscope is not for me. So, maybe a better use is to find a young student scientist wannabe or one of my young grade school acquaintances that could make better use of the Galileoscope!
Until next time, here from our burrow, stay safe, as we recover more of our freedom,