The little fiesta for Game 4 went well and my Cavalier fans went home happy. I had fun telling them how the Warriors were going to come back. In the first half I believed it. In the second I was just having fun with them. (If you missed it or are not a fan, the Warriors, who would win the league championship if they won last night, were 15-20 points behind for most of the game but they have a history of winning such games at the last minute. If you’re not a fan, it’s not important.)
The beginning of the night really took me back to my days working in the Bobcat Grill in my home town. I fried chicken for the group, each of whom brought something – a potluck snack. I missed most of the first quarter as I was frying in batches in my small kitchen. Frying things tends to make the cook smell like frying things so the smell, a powerful memory trigger, took me back. Then I would bring a batch out and return to the kitchen. By the time I got the next batch out, the previous was gone. What really took me back was how efficiently my hardwork was converted to empty plates outside my sight. I remember Friday and Saturday nights at the grill where I cooked steadily for hours and, yet, no food accumulated. I realize that is the point but it is always odd to see.
After the game, I had “promised” the group that I would take them out to show them the Moon and Saturn, which at midnight here are virtually straight overhead. I put promised in quotes because I suspect I was more excited about doing this than they were. I’ve had a few students ask to have a look through the scope but none of them were in last night’s group. We have a group touring in the south and another who took a trip with their homestay family. These absent students make up the bulk of those who have shown interest in my constant banging on about astronomy.
So, we tidied up a very little bit and headed downstairs. I’m pretty much in the center of Santiago, under a layer of smog, surrounded by miles of lights. The Moon and Saturn are two of the very few objects that we could see well. We went to the little parking area behind the apartment building and found a reasonably dark spot. They were entralled. I had suspected they would be. The Moon is an incredible view through any scope and people who are unprepared are blown away by the fact that they can actually see craters. Of course you can see a lot more than craters and they each fought to get a second look. I was home, so in no hurry.
Then I moved to Saturn, last night just a few degrees from the Full Moon. I have a telescope designed for wide-field view. I didn’t intentionally do that but that was the mirror I got and it made for a much more compact scope. Each mirror (or lens) has two important properties that are dictated by their shape: aperture and focal length. Aperture is how wide the mirror is – my scope here is 8″ (20cm) in diameter – which controls how much light the telescope collects. The bigger the mirror/lens, the fainter the object that can be seen and the greater the resolution (how much detail).
Focal length is how far from the mirror the focal point is. The mirror is parabolic (concave) and focuses light to a point. This is how the scope works: take light covering 8″ and focus it so that it fits through your pupil which is just a few millimeters in diameter. My telescope has a focal length of 32″ (80cm). The lower the ratio between focal length and aperture, generally, the wider the field of view will be. Field of view is simply how much sky one sees through the eyepiece. Another way of saying it is, the lower the ratio of focal length to aperture, the lower the magnification will be.
My focal ratio (focal length/aperture) is, you have surmised, 4.
That is very low. And, so, I can see a huge swath of sky but at fairly low power. This is exactly the opposite of what you’d want for the Moon and, especially, Saturn where you’d want high power so as to see the very small planet in greater detail. However, if the focal length were longer, the poles would have to be longer, creating a longer moment arm, necessitating sturdier construction, meaning a heavier, bulkier scope. Short focal length is better for my purposes with this scope.
You use the tool you have, so we took a look at Saturn.
I was pleased to see that the view was pretty nice. I was able to get to a pleasing view at 100x with my zoom eyepiece (one controls magnification via the eyepiece). I stepped back to give the students a look. We ended up on this one for a long time as they were more impressed by Saturn than the Moon. That is, again, a general trend. Saturn is amazing. It is intrinsically beautiful. I’ve never encountered someone who doesn’t think Saturn is pretty. Also, most people think the rings are some tiny thing that can only be viewed with huge, professional grade telescopes. That misses how lousy telescopes were when people first turned them on the sky and discovered the rings. My little Dob would, up until the mid-18th century, have been the greatest telescope on the planet.
In any case, we spent quite a while on Saturn only being interrupted by the night watchman for the building who came to see what we were doing. We were set up right under a security camera. I was disappointed that he refused a look.
The students had sharp eyes. They picked out the Cassini division in the rings without suggestion. They spotted three moons, which blew me away. I had picked them out but was surprised they did. Two of the students claimed to see them easily. These were pretty good observations for an 8″ scope at 100x. The seeing was pretty good (meaning the sky was steady) but, more importantly, it meant they were paying close attention to the view in the eyepiece. Saturn will do that to you.
I finished by showing them the Jewel Box, which was better than I’d thought under our crappy skies and then Alpha Centauri which surprised because it is double. Before turning in, the students asked for another look at Saturn so we finished there.
I have long thought that Saturn is the object everyone should see first through a telescope. I’m probably biased because it’s the first object I remember seeing using the C14 at Southwestern observatory where I grew up. Of course, I also saw Jupiter and NGC 4565 (yes, I actually clearly remember it). I was seven and hooked. But Saturn is the one that stood out. If you’ve seen Saturn in a telescope you know what I mean. If you haven’t, you owe it to yourself.
The beauty of the Moon, Saturn and Jupiter is that they offer the untrained eye a wealth of beauty and detail that other astronomical objects simply don’t. There is no need to use averted vision or exercise patience for stable seeing. Their beauty is plain to see. One does not learn to cook by first attempting a souffle, one makes a sandwich. A few good ingredients between two slices of fresh bread and you have something that anyone can make and all will enjoy. If you acquire the taste, you can work your way up. Thus it is with viewing objects through a telescope. Start with objects that are easy to see and which will please even the most jaded soul when viewed with a crude telescope under a lousy sky. If they acquire a taste, they can come back for more subtle flavors.
Having a look at the Full Moon at our pristine observing site.
Moving to Saturn. This is a photo I took back home with my “big” scope. The Cassini division is the black division that splits the rings in two (there are many divisions – check out the photos from the Cassini spacecraft which was named for the discoverer of the division in the ring).
Having a look at Saturn.