Yes, I know, I initially said that there were only going to be two of these entries, but they grew so long that I decided to split them up into three – and I’ve already edited where I said there would be two. The final big changes over the past 35 years have all been because of computerization: computerized scopes, digital cameras, and computerized information constantly at your fingertips via the internet.
Obviously, computerized scopes were nonexistent in the days before the personal computer. But as the mid-80s rolled around, someone got the bright idea of hooking a computer up to the scope to track the revolutions of the gears in the motors to enable you to know the RA and declination of where you were pointing. Both the precision and pointing abilities of this system kept on improving over the years until now, when we have optically encoded tracking. This is the same way your computer knows how much your mouse has moved – it has a lens that actually “looks at” what’s moving and “knows” how much it has moved.
This has been truly revolutionary for me, personally, and for anyone else who wants to observe from the heavily light-polluted cities in which most of us live nowadays – and which is only getting worse and worse, unfortunately. Sure, our limiting magnitude (based on aperture) becomes even more limited because of the overwhelming LP. We can’t see as deep in the city as others can see out in the sticks. But, as this entire blog hopefully shows, we still can see, and can see a lot. Although starhopping is also possible in the city, it is a time-intensive process. Goto scopes let you see far more than you’d be able to find on your own, and in much less time. This is really the wave of the future as the vast majority of people with disposable income to buy telescopes live in light-polluted cities and still want to be able to see something other than the moon and planets.
I cannot begin to tell you how important this has been to me, and my observing from the light-pollution dome that is Manhattan. My current count of DSOs is about 35 Messiers, a handful of Caldwells, at least 70 or so NGCs, and dozens of double stars, too. And I’ve seen all eight planets. I’ve seen things you people wouldn’t believe, things that I never would have seen otherwise, all thanks to computerized goto.
Neither were there any AP rigs. If you wanted to do AP, you needed an expensive SLR film camera that was fully adjustable as to exposure time, with a removable lens so as to attach a T-mount to get it onto the scope. I had one of these, and experimented briefly with shots of the moon, thanks to the free film I got from a photography class I took as a sophomore in high school. But there was only so much free film. Buying film was expensive, and I have always been cheap, so the experimenting was brief too. And, of course, unsuccessful. In the early 80s, CCDs (charge-coupled devices; in other words, digital camera chips) were just coming into view as an alternative to film, but they were even more expensive and a complete mystery to us. Now, with DSLRs, smartphone cameras, and webcams, they are ubiquitous.
This has led to an absolute explosion in digital AP. As I discussed a couple of blog posts ago, amateurs with rigs that cost only about $1500-2000 or so are able to take pictures that make the professional observatory photos of my youth look clumsy and amateurish by comparison. I see these gorgeous astrophotos in my Facebook feed every single day now as part of a group called Telescope Addicts, taken by talented amateurs with easily obtainable equipment, from around the world. And with the CCD, some of the best of these astrophotos come from scopes that have only 2.5, 3, or 4 inches of aperture – apos, all. The photos of planets are similarly astonishing, although taken through larger scopes, up to 14 inches – about the same level of detail as what Pioneer 10 was showing us on approach to Jupiter 40-odd years ago.
This is because, in addition to the ability to capture the photons digitally, they can be manipulated digitally as well. Long exposures taken over many nights can be seamlessly stitched together. This is usually done with video taken at 30 frames per second. Any frames with less than perfect clarity and/or focus due to poor seeing can simply be chucked away, leaving only the sharpest and clearest frames. Programs like Registax and Autostakkert do this relatively simply, and for free. And if you don’t like the end result, you just adjust your settings. Not something that could easily be done with film.
Taking the long view back from 35 years out, what is so very different now than then as an amateur astronomer is that we are fully awash in information with the internet. Although I admit, I was certainly willfully ignorant back in the day – from being too cheap to buy some basic things, like a star atlas, or other observing guidebooks – it doesn’t all come down to that. I did have The Messier Album, which was well-used and well-worn. I also had a couple of books on general astronomy, although they weren’t on observing in particular. And I subscribed to Sky & Telescope for a few years, which did have articles each month detailing astronomical events and objects to observe.
But none of that could have helped some of the points I made above. If I had wanted to observe the GRS, or a shadow transit, there was just no way to do it, barring contacting the US Naval Observatory to find out when they occurred, which I wouldn’t have known to do anyway. Knowing that Mercury was viewable for a few days? Lunar occultations of Venus, or Aldebaran, like those that occurred over the past couple of months? These things were just not going to be observable back then. The only way to have caught an astronomical event would have been completely by chance – either by it happening just randomly before my eyes, or by just happening to read something about an upcoming event in advance in the newspaper. And considering the fact that I only “looked” at objects – I didn’t observe back then because I didn’t know about the effects of seeing (I spent one minute on an object as opposed to, say, five) – those slim chances of randomly seeing an “event” were even slimmer.
Now, the sky can be a dynamic place. S&T graciously provides calculators letting me know when the GRS will be visible, and when moon shadow transits will be happening. The internet floods me with information about occultations, conjunctions, oppositions, triple-shadow transits, and the like. I am never without knowledge of some celestial happening. And for me, that is where the excitement lies. Yes, it’s wonderful to see certain DSOs, but they’re completely static. It’s nice to see something actually happen up there every now and then.
Even if I had been able to identify other interesting objects to view in catalogs such as Burnham’s, I didn’t have a star atlas to find them on so I could starhop to find them. The only other alternative would have been to use the celestial coordinates he provided in the handbook. I certainly didn’t (and don’t) know how to polar align, other than to roughly point the RA axis toward Polaris – there were no polar scopes then. And I definitely couldn’t have used the setting circles on the scope to any degree of accuracy to allow me to find something.
As an example of this, I didn’t even know of the existence of the Double Cluster, one of the absolute showpiece objects of the sky, twin jewels of the night, until a year and a half ago, when I saw it in the S&T Pocket Sky Atlas. If it wasn’t in The Messier Album or on the monthly sky map in the centerfold of S&T, it may as well not have existed for me – and, as a teenager, it didn’t. There was little way to satisfy any intellectual hunger you might have had.
The change in information available with the internet is enormous and cannot be understated. Formulas to calculate everything you ever wanted to know about your scope and EPs are just a spreadsheet away. And so is anything you might want to observe. For example, you can go to Tonight’s Sky, enter your parameters as to where you are, when you want to observe, what your limiting magnitudes are, and boom, there’s an observing list generated for you automatically. You can then click on the links provided, or go to Wikipedia, and find out everything you ever wanted to know about those objects.
And it is the knowing that makes so much difference. It is so much more interesting to look up at the Ring Nebula and the Dumbbell and know that what you’re seeing is what our sun will end up becoming in a few billion years; or to look up at the Pleiades, and know their relatively youthful age, their distance, and that the light I’m seeing from them left roughly when the Spanish Armada was being destroyed by England; or to look up at the Great Orion Nebula and fully understand that you’re seeing a star nursery. Even though M81 is just a tiny little gray smudge of light, it is thrilling to know that that when I saw it, that light had travelled 12 million years across the universe to get into my eyeball – long before we humans were Neanderthals, or australopithecines, or anything even close to great apes.
Now you can open an easy-to-use – and free! – program like Stellarium and pinpoint exactly where all of these objects are. And if you don’t feel like hauling your laptop outside with you, there are plenty of apps for your phone, like Sky Safari, that’ll do exactly the same thing, and even identify what you’re looking at up in the sky just by pointing the phone in that direction. Catalogs like Burnham’s and printed star atlases have been made as obsolete as librarian Romney Wordsworth from The Twilight Zone. Between now knowing that these objects exist, and understanding what they are and how they came to be, and being able to find them, either with my computerized mount, or by using Stellarium or some other program to starhop with, hundreds of Messiers, Caldwells, and NGC objects are now available for me to view. And that is a wondrous thing.
What will the future hold? One thing that has occurred in the 20th century is the invention of entirely new types of telescopes – Schmidt-Cassegrains, Maksutov-Cassegrains, Maksutov-Newtonians, Ritchey-Chretiens, even apochromatic refractors. These designs did not exist 100 years ago; and with the exception of the Mak-Cass in the form of the exquisite Questar, none of these designs were available much more than 40 years ago. Each of these designs in turn has gone from exotic to commonplace; each of these designs has improved on all existing designs. And with each of them becoming more commonplace, their prices dropped significantly. What other new designs are out there that have not even been dreamed of yet?
I, for one, am hoping that the cost of the adaptive optics currently in use in large observatories will eventually trickle down to become affordable by amateurs. Large observatories are able to achieve the detail and resolution that they do from beneath the canopy of earth’s distorting atmosphere through the use of adaptive optics. They shoot a powerful laser up into the sky, creating, in effect, an artificial star. Computers actively monitor the turbulence in the atmosphere – the seeing – by determining its effect on what should otherwise be a point source of light. They are then able to use mechanical actuators beneath the mirror segments (all large observatory mirrors nowadays are made not from a single piece of glass, but from a number of hexagonal mirrors fitted together) to precisely deform and reshape the mirrors to almost completely counteract the effects of atmospheric seeing. The actuators are able to deform the mirrors at a rate of up to thousands of times each second. The gain in resolution is about 25-fold, from about 1 arc second down to 30-60 milliarcseconds.
Having a mirror that could deform to meet local seeing conditions would mean that local seeing conditions wouldn’t matter – an average night or even a poor night would always be a perfect, pristine night! Magnification would increase tremendously – to the 500x and 600x you see commonly advertised on the side of terrible department store scopes, and beyond. Man, how I’d love to see that improvement in my scope!
Here’s to the next 35 years!