Back in 2008 I got a fantastic 200mm dobsonian mounted reflector telescope. One of the first objects I wanted to view was Mars. I remember picking my kids up after school and seeing the beautiful reddish orange planet hanging above the school building and thinking I can’t wait to get home to have a look at it through my new telescope. The capability of new telescopes and the expectations of new telescope owners can be widely different and this was certainly me when I first trained that telescope on Mars. Obviously when you first get a telescope there’s an assumption that that you pull it out of the box, set it up and off you go. Generally it kind of works like that, it’s just in reality the time frame is considerably longer.
So I get home, and by this time it was getting quite dark. I get the telescope out and test it on Mars. I had already set it up during the day and had a quick look at a distant ridge through a couple of different eyepieces so I wasn’t completely useless when I dragged the telescope outside. Back in 2008 the internet was just as helpful as it is now, with lots of helpful tips on how to set your telescope up and lots of scary, unhelpful advice to put any newbie off. Depending on what I read the views on collimating my telescope ranged from physically impossible through to it’s so easy it practically collimates itself. Like most things, reality sits somewhere between the two extremes. I had a laser collimator that came with the scope so I thought, awesome, this is going to be a walk in the park. I put the laser collimator in, lined it up and played with the primary mirror adjustments until the laser bounced back to the centre of the circular graduated scale. I was so pleased with myself that I had nailed this collimation malarkey so easily. Unfortunately it wasn’t quite the case. For some reason I thought I would check the collimation by testing it through the collimation cap. I was thinking at the time that the super duper laser thingy must be way better than a hunk of plastic with a hole in it. When I looked in the tiny hole, the picture was not a nice bunch of concentric rings with a circular sticker from the primary mirror in the centre. It looked more like what someone would expect after the telescope had been impacted by a bus. Of course I was thinking, nah, trust the laser!
I set the telescope up outside on the path in a perfect spot to view Mars. This was going to be awesome, I was imagining viewing the slopes of Olympus Mons, taking in the polar ice caps and seeing loads of other fantastic details, move over Spirit and Opportunity, the mighty XT8 was about to count grains of sand on the Martian surface! So I found Mars, visually, and lined up the telescope – looked in the eyepiece to see nice big fuzzy donuts that weren’t at all symmetrical. No problem, I just needed to focus it. So I did that and the star in the eyepiece looked very unusual – kind of like it was pinched on one side, that star wasn’t Mars. So I encountered my second problem (collimation was the first though I didn’t know it at the time) which was how to get stuff in the eyepiece. The finder scope was clearly designed for this job so I eventually found Mars in that, and then looked in the eyepiece again. Still no Mars! Ah, so the finder scope and the reflector tube were not aligned. I lined up on a bright light across a paddock from the house which was easy to find in both the main telescope and the finder scope. Presto! Both were aligned, now back to Mars! I lined up Mars in the finder scope and excitedly looked in the eyepiece and …. wow! What’s that? A pale dot? That looks a bit reddish? This was the point where my expectations got a solid reset and I learned that you just don’t point a telescope at the sky and see Hubble like pictures.
The pale dot was rather uninspiring, mostly to do with the fact that I had done the worst attempt at collimation in the history of astronomy. This had to be rectified so I got the collimation cap out (and the instructions) and pointed the scope at the lounge so there was plenty of light. First the secondary was put in the right spot and the adjustments were made to the primary. The rings all seemed to line up well this time. So it was back to Mars with a smaller eyepiece and there it was, the pale reddish disk transformed into a reddish orange disk with a clear light area near a pole and some dark patches on the disk. My disappointment at not seeing the level of detail akin to a rover’s camera was gone in a flash as I was observing another world for the first time. I spent ages watching Mars traverse the field of view over and over as I moved the telescope to catch up and be ahead of the direction of travel. Wow, it was amazing!
The featured image at the start of the article is the Moon through the same telescope discussed above, taken with my cellphone and ten years later.