As I've chronicled in these pages for nearly a decade (!), autumn is my favorite time to observe the heavens here in Washington, DC. The air is crisp, the mosquitoes are scarce (usually), the wildfire smoke has abated, and the atmosphere is often quite steady. Unfortunately, I haven't had much time to observe this autumn - I'll explain why in a minute - but recently I did have a chance to catch a glimpse of the waxing gibbous Moon. 

Better yet, I caught that glimpse with a brand new telescope: a Takahashi FC76 DCU. A few weeks ago, I decided to sell my workhorse, a telescope I've long praised in these pages: the Takahashi FC100DZ. It was a tough call, but my TSA 120 is light enough and, to my surprise, cools down quickly enough to make the 100DZ a little superfluous. At night, I often asked myself: why would I use the four-inch refractor - the DZ - when I could use a five-inch (the TSA) instead and get a slightly better view? 

Enter the little 76 DCU. It's that much lighter than the DZ, making it so easy to carry that I scarcely feel it - even with a diagonal attached. It doesn't have a sliding dew shield, which would be a drawback if it were a little bigger. But for a three-inch refractor, the slight reduction in setup time is a blessing. 

So yes, the 76 DCU is a wonderful telescope, and it may well be better for my purposes than the 100DZ. When paired with the TSA 120, it should give me a wonderful one-two punch for urban observing. 

And why have I been busy lately? My new book! Ripples on the Cosmic Ocean, a book that shows how the solar system mattered in human history, made its debut about a week ago. From doing a Reddit AMA (my first!) to writing a series of articles about everything from solar storms to Martian canals, it's been a hectic stretch. I also completed a heap of interviews, including this one for the Planetary Report, my favorite space podcast.

On top of that, I created six short videos to introduce the book - its big arguments, the evidence I use, the methods I follow, and why it all matters. You can start watching them right here. 

It's funny: I started writing this little blog because I wanted to remember the things I saw under the night sky. But the more I saw, the more it shaped how I wrote Ripples, and the more people I reached through this blog. Ripples and AstroJournals.com now feel like two sides of the same coin - the coin of the profound connection I and so many others feel to our cosmic environment. 

For one week every year, I get to experience a truly dark sky – a 1 or at worst a 2 on the 9-level Bortle scale. At Riding Mountain National Park, near the western edge of Manitoba in the Canadian prairie, the night sky can be so perfectly black, but so alive with glittering, colorful stars, that I can imagine what it might be like to gaze up from the surface of the Moon.
 
Not this year. The cause: wildfires, burning with unprecedented ferocity in unusually hot, dry forests of northern Manitoba and Saskatchewan. Vast plumes of wildfire smoke have wafted south all summer, blotting out the stars (and making it painful to breathe). It’s sad to think that, just a few years ago, I never worried that smoke would keep me from using a telescope.

Now, it’s a fact of life – a new reality that didn’t need to be. As a professor who often studies climate change, it's a sobering thought. 
 
Now, there were a couple nights at Riding Mountain when the wind shifted to blow from the south, holding off the worst wildfire plumes. On one of those nights, I slipped outside with my Vespera Pro. To my dismay, I could just barely make out the ribbon of the Milky Way, undulating across a sky that was far from the velvety black I’ve grown used to.

What’s worse, the Vespera would not track anything. As I huddled in a shadow near our rental cottage, I tried the Trifid Nebula, then the Eagle Nebula, then the Dumbbell Nebula and the Hercules Cluster, all to no avail. It was now well past 1 AM, and I was getting desperate. Mosquitoes, no longer daunted by repeated applications of bug spray, were beginning to bite me in droves.

​And it was dangerous. Riding Mountain is a wild place. There are well over a thousand bears in the park, not to mention wolves, cougars, and other animals that could easily kill an amateur astronomer. I couldn’t see anything, and I imagined that every creak and crunch was animal stalking closer.
 
Finally, I gave up. What had happened? Why did my Vespera fail now, and not in the light-polluted DC sky? Eventually, I found the reason: I had failed to input my new GPS coordinates. I’d assumed – foolishly – that the telescope automatically detected its location.

Back in Winnipeg, I waited for a clear night between wildfire plumes. Finally, it came, though atmospheric transparency stayed low. I just wanted to check whether the Vespera would work when I’d entered the right coordinates. To my chagrin, it did – and I took a mediocre exposure of the Hercules Globular Cluster that was still better than anything I’d managed with another smart telescope.

​Any look at the Hercules Cluster – M13 – is always a little special. As I wrote several years ago, I often think of the Arecibo Message, a radio signal beamed towards M13 on November 16th, 1974. In about 25,000 years, that message will reach the approximately 500,000 stars in the cluster. Any listeners will learn about human physiology and technology – and they’ll receive a map of the solar system. In another 25,000 years, something on Earth may receive a response. Our distant descendants, I hope.
 
In any case, after arriving home from Canada, we travelled to the coast in Delaware – another annual ritual. It’s not as dark there as it usually is in Riding Mountain (I’d give it about a 5 on that 9-level Bortle scale), but still, our beach trip is usually my next chance in the year to observe beyond our light-polluted DC skies.
 
Readers will know that I tested the EVScope 1 and 2 during these Delaware getaways, and both had their virtues. This time, I tried the Vespera Pro, and of course I was sure to enter the right coordinates. On the final night of our stay, the sky cleared. Transparency and seeing were both about average, but the stars seemed a good deal brighter than they had in Riding Mountain. Mercifully, no wildfire smoke had made it this far south.
 
At about 11:30, I activated the telescope just as the Andromeda Galaxy emerged out from behind a nearby building. As I reclined in a sunroom, drinking mead, I began a long exposure. A great thing about the Vespera app, Singularity, is that it works in the background while you’re checking the internet, for example, or writing an email.
 
A less great thing, perhaps, is that there’s a mismatch between the time the telescope focuses on a target – such as the Andromeda Galaxy – and the exposure time provided by the app. I found the time was consistently about 30% off, so that a 30-minute exposure actually took 45 minutes. It’s something to consider when planning a night of observing.
 
In any case, a 33-minute exposure of the Andromeda Galaxy yielded the following result:

This is very close to the raw image. I’ve made a few small adjustments in my Pixelmator Pro software – mostly just denoising – but this is what you can expect under a suburban sky with the Vespera Pro. It is, by far, the best picture I’ve taken or anything other than the Moon. I was delighted to capture detail in Andromeda’s satellite, the dwarf elliptical M110, at the top left of the image.
 
And just think: there are probably more than a trillion stars in this picture, shining at us with light that’s two and a half million years old. It boggles the mind. And then consider that those stars are rushing towards us at 110 kilometers per second. Someday, they might join the stars in the Milky Way to form one giant elliptical galaxy – though a recent study suggests that Andromeda might just sail past us instead. What a sight that will be.

Anyway, after taking this exposure I decided to forego sleep and image my favorite deep space object: the Triangulum Galaxy. I don’t know why I love it so much. Perhaps because it’s so ignored, compared to Andromeda, despite being a gigantic star city in its own right: at 60,000 light years across, the third-largest member (by far) in our local group of galaxies.
 
This time, I took a 30-minute exposure while downing the last of my mead. The result satisfied me even more than my shot of Andromeda. Again, I’ve done little more than eliminate a bit of noise from the following shot.

To my astonishment, it’s been five years since I took my first electronically-assisted telescope – the EVScope 1 – to the beach in Delaware. It was a frightening time, for many reasons, but I still remember my delight at the blurry pictures in the telescope’s eyepiece. No, it wasn't quite the same as using my Takahashi refractors, but I felt new possibilities opening before me: the broader universe, beyond our solar system, that had previously felt just out of reach. 

The Vespera Pro is less expensive than the EVScope was (or than the EVScope 2 remains today). It’s worth reflecting on just how much the technology has improved. The slideshow below alternates my 2020 EVScope exposures of the Andromeda and Triangulum galaxies with the exposures I just took with the Vespera Pro. Note the much broader field of view provided by the Vespera - a must when imaging large, diffuse objects, such as nearby galaxies. 

It's true that you could still take better astrophotographs by making your own rig, and you could probably do it with less money. It's also true that, if I ever get around to learning how to use astrophotography software, such as PixInsight, my Vespera photographs would get that much better.

I suspect that, in another five years, electronically assisted, smart telescopes will match the performance of custom rigs - and they'll be a whole lot easier to use. Even if that never happens, it's clear that such telescopes, once widely derided as a fad, will have a place, perhaps even a dominant place, among amateur astronomy equipment. 

At around 10:00 PM on April 17th, I waited beside a railroad track that winds along the banks of the Susquehanna River in rural Pennsylvania. I had found a nook of open sky between trees and telephone wires, and in the darkness I could barely make out the glow of the Milky Way. I booted up a Dwarf 3 electronically assisted telescope. Readers will know that I’ve tried the EVScope 1 and 2, and then the Vespera 2. The Dwarf 3 is more compact than those telescopes, it’s much cheaper, and it promises comparable performance to the Vespera. I had to try it out.
 
As I waited, a distant rumbling intruded on my thoughts. It occurred to me that the rumbling might have started some time ago. The ground began to tremble, ever so slightly. And then a shaft of blinding light slashed through the night. I grabbed my telescope, halfway through its exposure, and ran. I made it to the front yard of my cottage, about 15 feet from the tracks, when a freight train thundered by. Car after car after car passed as I stood, gawking. Then it was gone, and darkness returned.

​It took me a while to regain the courage I needed to set up the telescope a second time. Since there was still no better place to observe than beside that railroad track, I tried again. I attempted two ten-minute exposures, one of Bode’s Galaxy (M81), the other of the M3 globular cluster. Both were high in the sky. I didn’t dare stay out any longer, and when I packed up, I counted myself lucky to have avoided a second train. These are the images that I acquired at such peril:

​Okay . . . nothing to write home about. I know for sure that it’s easy to improve some of the problems in this picture, namely the star trailing caused by inadequate tracking. But I also think that the small aperture of the Dwarf 3 – just 25 millimeters! – may add more noise to its images, and no doubt requires longer exposures to bring out subtle details in nebulae or galaxies. I was impressed by the Dwarf’s software, which is incredibly easy to use, but my first experience with the telescope underwhelmed me.
 
I had sold my Vespera to try the Dwarf 3, and now I can’t say I was very happy about the swap. Fortunately, I found a second-hand Vespera Pro on sale for a fair price. I decided to get that telescope, and sell the Dwarf, admittedly before I had a chance to experiment with that telescope’s full abilities.

​As you can see . . . there’s a difference. The Vespera is bulkier than the Dwarf but much smaller than the EVScope, and on some objects aperture does make a difference. A ten-minute exposure of the Whirlpool Galaxy (M51) in the light-polluted sky, for example, didn’t look quite as good as the images I’d acquired with my EVScope 2:

​And then there’s the setup time. The Dwarf and EVScope are ready to go within a minute or two after setup. The Vespera requires about five minutes. Then again, it tracks stars more effectively than the other telescopes, and it focuses automatically.  So, on most objects, I judge the Vespera Pro to be the best electronically assisted telescope on the market – and I’m not sure it’s close.
 
My plan now is to try the Vespera next month under the truly pitch-black skies of Riding Mountain National Park, Manitoba. With any luck, there won’t be much wildfire smoke in the atmosphere, and I won’t be attacked by a cougar or coyote.  We’ll see!

It's been a while, but my lack of new posts has a good cause: I finished my next book, and it's just about ready to debut later this year (October 28th, to be precise). The book tells - as my publisher says - "the untold story of how environmental change throughout the cosmos shaped human history." I hope it's a good read! It certainly took me long enough to write. And one interesting aspect of the book is that it draws not only on my research as an academic, but also on my experiences as an amateur astronomer - experiences I've chronicled in this blog. 

Another reason for my silence is that the weather has been pretty bad here in Washington, DC. Either it's been cloudy, or the atmosphere has been turbulent, or (lately) it's been smoky, owing to the fires in Canada. Now, on November 8th of last year, I did manage to step outside with my TSA 120 on a glorious night for astronomy. I wanted to write about that - until I was swamped with last-minute editing work. 

Had I had time to publish here in November, I might have had more to write. But I do still remember the look of the Galilean Moons that night. The seeing was so stable - and the TSA 120 is so good - that the moons resembled not points of light, but hard little discs, each with a different color. At a magnification of about 150x, I experienced the illusion that if I magnified just a bit more, I'd be able to see surface detail on a couple of those little moons. Unfortunately - as is typically the case here in DC - cranking the magnification beyond 200x did not produce a better view. 

A few months ago, I also experimented with a new "smart" telescope: the Dwarf 3. I intend to write about that at greater length in a forthcoming post, when I'll compare the Dwarf to the Vespera and EVScope. I'll say for now that I was nearly run over by a train in rural Pennsylvania while imaging M81 (Bode's Galaxy). 

In any case, a couple nights ago the wildfire smoke mostly drifted away, the atmosphere was mostly stable, and I stepped out with my TSA 120 to do one of the things I love most in life: exploring the infinitely complex landscapes of the Moon when our neighboring world is halfway illuminated. I set up my telescope in the courtyard of my building, and as I started peering through the eyepiece I could just hear a neighbor beginning to play soothing - and actually, slightly eerie - melodies on his acoustic guitar. It made for a perfect soundtrack as I worked my way from the enormous gash of Vallis Alpes in the Moon's northern hemisphere (it always looks to me like someone grazed the Moon with a giant knife) to the tidier and more diminutive straight line of Rupes Recta in the south. 

As usual, I took pictures by holding my iPhone up to my Delos eyepieces. I've become pretty good at holding my phone with a steady hand, but amateur astronomers know that, in any snapshot of the lunar surface, the inescapable undulation of the atmosphere tends to blur the fine details that are visible with the naked eye. So it is in the pictures, above. They may look pretty impressive - especially when you consider that I took them with an iPhone - but the view was actually that much better. Limitless detail, and endless complexity. 

One of my weaknesses is that I like to compare and rank things - it must be genetic, because my eight-year-old daughter has developed the same trait. It also seems to be a common affliction of amateur astronomers. Naturally, after having had a particular good observing session with the TSA 120, I began to consider how the telescope measures up to others I've tried - when it comes to lunar viewing, at least. 

In short: I think it measures up to anything I've used, and that includes the Mewlon 210, the TEC 140, and the APM 140. Actually, that might not be going far enough. On the Moon, aperture matters, of course; so does the overall optical quality. But two characteristics that really stand out are a lack of false color (a common affliction along the lunar limb in all but the finest apochromatic refractors) and crisp detail to the edge of the eyepiece (not usually a strong point of a catadioptric or Dall-Kirkham design).

This is where the TSA 120 excels. Any false color or softness in my pictures is an artifact of my iPhone camera. In reality, the view is totally color-free and sharp to the edge of the eyepiece. This is why I'd have to conclude that the TSA 120 might just be the best lunar telescope I've used. It's amazing to have so much capability in such a relatively light and compact package. 

​

I haven't written much this year, owing in large part to my frantic quest to finish revising my next book, Ripples on the Cosmic Ocean. Revising a book always makes you wonder why you decided to write one in the first place. But with any luck, Ripples will be out next year.

In a future entry, I'll describe the book and explain how it draws on some of the observations I've shared in this blog. However, now is the time to describe a trip I took this week to Flagstaff, Arizona, where I finished up some research and gazed through the extraordinary telescopes at Lowell Observatory on Mars Hill. 

If you're familiar with the history of astronomy in the United States, you likely know something about Percival Lowell. It may be because you've read about the so-called "canals" of Mars. Lowell was sure they existed, and at Flagstaff he built a state-of-the-art observatory to explain their purpose. For reasons I describe in my book, Lowell decided that the canals were built by aliens. He played a key role in convincing millions that were were not alone in the universe - except, of course, the canals weren't real, and the Martians weren't either. Lowell died in 1916, as astronomers were losing faith in his canals. Yet his observatory lived on. It was here that Clyde Tombaugh discovered Pluto, and here that Patricia Bridges and other cartographers mapped the Moon so that NASA could plan the Apollo landings. 

Lowell was more than just a deluded failure, however. Among his genuine breakthroughs was the idea that big telescopes should be placed where the seeing was good and the atmosphere was steady. One reason he was so successful in defending the notion that canals crisscrossed Mars is that he could claim that the seeing at Flagstaff was better than it was over other big observatories. It seemed that the Arizona air allowed him to see what canal skeptics could not.  

I travelled to Flagstaff with a little telescope to test its legendary seeing. I managed to cram a new Astro-Tech AT72EDII into my carry-on suitcase (along with its mount, tripod, finder, diagonal, and eyepieces), and I still had enough space for my clothes. At twilight I unpacked the little refractor atop Mars Hill and pointed it at the Moon. It was quite a place for first light. 

My view of the Moon was quite remarkable, given the size of the telescope. Indeed the air seemed unusually steady on Mars Hill, as Lowell so often insisted. My tripod, however, was totally inadequate for my telescope. Worse, the weight of the telescope's impressive, two-speed focuser made it impossible to balance on my mount. It kept sliding backwards, so I had to adjust the tension on my mount until nudging the telescope made it wobble for at least five seconds. 

Still, the view was good enough that I grew even more excited to use the observatory's telescopes. In 1895, Lowell commissioned a legendary telescope-making company, Alvan Clark & Sons, to construct a peerless achromatic refractor for his Mars observations. With its 24-inch aperture and long focal length, it might have been the best planetary and lunar telescope in the world when mounted atop Mars Hill​.

After I packed up my little telescope, I scurried further up the hill to the distinctive wooden dome that Lowell commissioned for his great refractor. I could just make out the swerving arc of the Milky Way as I approached the dome. It was a funny thing, moving from a $500, 3-inch refractor to a 24-inch behemoth that was, once, one of the world's great scientific instruments. For a few minutes, the observatory's staff let me gawk at M13, the Hercules globular cluster. It was, I must admit, quite faint, but there were stars resolved all the way to the center of the cluster. I'd only ever seen the cluster as a dim blob through a traditional telescope; this was something different. 

After I left the dome, I walked even further up the Hill, past the telescope that found Pluto, and around to a little pavilion where the observatory's helpful staff had setup a collection of high-powered telescopes. There was a TEC 140FL, a 16-inch Meade Schmidt-Cassegrain, and - most exciting for me - a 32-inch Dobsonian. 

First, I gazed at Saturn through the TEC140. Readers of this blog will know that I've owned the TEC140ED, so I thought I knew what to expect. I was wrong. Saturn looked worse through the TEC140FL than I'd often seen it through smaller refractors in Washington, DC. Lowell himself acknowledged that there were nights when the seeing at Flagstaff was not quite sublime. I wondered whether the seeing had deteriorated since I'd viewed the Moon. Or was the magnification of the TEC 140 just too high? 

Every year, Saturn's rings take on a different tilt when viewed from Earth. It was impressive to see them nearly edge-on, though I miss the Saturn of a few years back. I couldn't see any trace of the Cassini Division in the rings, and I wonder whether that was due primarily to the seeing or the tilt of the rings. I suspect the former.

Next, I clambered up a ladder to look at the Swan Nebula through the big Dobsonian. This was more impressive. The Nebula seemed about as bright as the Orion Nebula through a four-inch refractor. I could make out countless stars, not to mention a great deal of fine, ethereal detail using averted vision. The waxing crescent Moon was still in the sky, and I wonder what the nebula would have looked like on a darker, moonless night. 

On the following afternoon, I took a cab to nearby Meteor Crate, hoping to see the wreckage of a little asteroid that smashed into Earth about 50,000 years ago. Having written about the crater and its history for a few years now, I was nevertheless astonished by its beauty, and the austere grandeur of the surrounding landscape. The crater initially looked a good deal smaller in diameter than I'd expected, but a good deal deeper. The shock-ripples in the stone around the rim appeared extraordinarily well-preserved. 

I also had another look at Lowell's big refractor in the light of day. I tried to imagine what it was like for Lowell and his assistants to gaze through its eyepiece, in the confident belief that they could map the works of an alien civilization. How eerie and exciting it must have been to peer through the eyepiece on those starlit nights at Lowell Observatory, waiting for a glimpse of the canals when the seeing stabilized in the desert air. 

For me, the night's forecast called for exceptional atmospheric tranquility and stability. Of course I had to go back to the observatory. This time I admired Lowell's mausoleum, its entrance engraved with quotes from his books that are still as captivating as they are mistaken. 

Then I marched back up the hill to use the TEC another time. The observatory's staff had turned it on the now halfway-illuminated Moon, and indeed it was a predictably impressive sight. I've had similar views, however, on many a decent night in Washington, DC. On a good night, the Moon has looked considerably better through my Takahashi refractors. I couldn't make out a single craterlet in Plato when I viewed the Moon atop Mars Hill. 

Next, I had a look at Saturn through the observatory's 16-inch Meade SCT. To my surprise, the planet looked far better on the previous night, when I peered it through the TEC. It was brighter through the big SCT, granted, but it was also a fuzzy, quivering mess. I've had far better views of the planet through a 3.5-inch refractor.

Some readers will disagree - this is a topic that has angered amateur astronomers for decades - but after years of using both apochromatic refractors and SCTs, I must at last conclude that in most atmospheric conditions, the refractors outperform much bigger SCTs - at least on planets, the Moon, and double stars. If I'm honest, it's rarely close. 

Once again, I came back to the observatory during the day. The observatory's staff set up an H-alpha telescope, and naturally I had a look at the Sun. This might have been the most impressive thing I saw on Mars Hill. The Sun is exploding with activity right now (quite literally, given the prominences erupting all over its surface). It was hard to a take a picture with my iPhone, but you'll see that I managed it. 

In my many years of research, I don't think I've visited a place I like more than Mars Hill. The staff are helpful, the history is enthralling, and the chance to use quality instruments in the thin, steady atmosphere is a true privilege. I'm still coming to terms with the fact that my 4- and 5-inch Takahashi refractors have given me far better views of Saturn and the Moon than I had using the bigger instruments at Lowell Observatory. It goes to show you that, as Lowell often insisted, the state of the atmosphere matters a good deal more than the size or quality of the telescope. And it also suggests to me, at least, that Lowell might have exaggerated the quality of the air at Flagstaff. 

The AT72 is also a remarkable little telescope. The hobby has its share of grossly overpriced equipment, but then it also has some remarkable bargains: little telescopes that approach the performance of larger instruments costing four or five times as much. The AY72 is one such bargain. It's not as good as, say, a TeleVue 85, but it gives you maybe 85% as much at a fraction of the size and, most importantly, the cost. I recommend it wholeheartedly. 

Our indefatigable news media seems to have transformed every full Moon into a show-stopping event. It's always a super blue wolf harvest something or other. To be fair, the hype stirs up a good deal of popular interest in our neighboring world, and to my mind that can only be a good thing.

Of course, amateur astronomers know that because a full Moon has no shadows, it can be unsatisfying to observe with a telescope. The craters, mountains, and rilles that are otherwise so obvious seem washed out in a sea of milky-white brilliance. Still, the trees in my backyard have not yet unfurled their budding leaves, and pockets of the night sky remain visible just steps from my kitchen. The other night, I couldn't resist setting up my Takahashi TSA 120 as the full Moon moved through a gap in the bare branches.

​Atmospheric transparency and seeing were both about average - at least in theory. In practice, conditions seemed to shift by the minute. Occasionally a watercolor softness blurred the Moon, but then it snapped into focus for many seconds at a time. For amateur astronomers, our atmosphere truly is a fickle antagonist. 

Using my iPhone, I don't believe I managed to get a picture of the Moon in its clearest moments. Still, just look at those mountains outlined in sharp relief on the limb of the Moon. Rarely have I managed to get such an obvious look at them. Crater rays, meanwhile, are actually a lunar feature that becomes obvious only with the Moon fully illuminated. It was wonderful to follow their tendrils across the the Moon's silvery regolith. 

​As for the telescope, what is there to say? Among apochromatic refractors, the TSA 120 is about as perfect as it gets. Nitpicking comes easy to me, but in this case there are no nits to pick. Actually, the telescope's size reminds me a little of the Vixen ED115S that I used to own (with its oversized Moonlite focuser). I thought the Vixen was the perfect size for a refractor, but the TSA might be even better. It actually feels a bit lighter and more compact, but the aperture is just a bit bigger. A five-inch refractor is a really ideal: it edges out the performance of a four-inch, but doesn't need a much bigger mount and tripod (which can be necessary with just half an inch of extra aperture). 

I recently acquired a DSV3 mount from Desert Sky Astro. This is a manual mount that isn't too heavy and seems extremely well made. It includes both slow-motion controls and a handy "quick balancing system" that allows you to easily compensate for the weight of different eyepieces. With just a flick of the wrist, the telescope stays balanced. It's a clever little feature that, I discovered last night, makes observing just that much easier. 

Readers will know that I'm a manual mount aficionado. When you don't have much time to observe, or if you want to avoid all hassle in a public park, there's simply nothing better. So far the DSV3 seems like the best medium mount I've used, and I've tried just about all of them. It's at least as well made as the best mounts on the market, and it includes features that its competitors simply don't offer. For the TSA 120, it truly is just about perfect. 

After I'd observed for no more than 30 minutes, the Moon rolled behind my building, and with fingers numb from cold I packed up my telescope. As I've mentioned here before, it's hard to think of a better use of time than exploring another world from the comfort of your backyard. 

Electronically Assisted Astronomy (EAA) has been around for a while. Not long ago, you'd get into it by buying a camera, attaching it to your eyepiece, hooking it to a monitor, and then watching as it combined - or "stacked" - images of nebulae or galaxies. Before long, the image on the monitor would take on the recognizable shape and color of a deep space object that, viewed unaided through the eyepiece, appeared as little more than a barely-perceptible smudge.

Gone was the romance of peering at the space beside that smudge (using averted vision) and imagining, say, the combined light of 250 billion stars. But, if we're being honest, the magic got a little stale when squinting at one equally dim blob after another. EAA offered no substitute for looking through a big Dobsonian under a dark sky. Its images paled in comparison to those that could be taken with a complicated astrophotography rig. But for those of us stuck in the city and unwilling or unable to try serious astrophotography, EAA let us see what otherwise seemed out of reach: the universe beyond our solar system.  

A few years ago, two startups - Unistellar and Vaonis - took the obvious next step by debuting an integrated telescope, go-to mount, tripod, and stacking camera. Both the EVScope (Unistellar) and Stellina (Vaonis) were small, portable, and remarkably easy to use compared to any telescope on the market. Both were priced far beyond the cost of their parts; it is, after all, expensive to sell a niche product as a brand-new company. Still, despite the exorbitant cost - I shudder to think of what I paid for my EVScopes - enough people bought the new "smart" telescopes that both companies seem to have prospered. 

When both the EVScope and Stellina succeeded, it was clear that amateur astronomy would never be quite the same. The technology would keep improving, and bigger, more established companies would get in the game. A maturing market, meanwhile, would permit economies of scale. Those who waited on getting the first-generation EVScope or Stellina reasoned - correctly - that prices would soon collapse. 

Anyway, I bought my EVScope 2 for about $5,000. Recently, Vaonis released its next-generation Vespera II for about $1,600. The Vespera II is much more compact, it has a more sensitive sensor, it focuses itself (unlike the EVScope), and it's built around an apochromatic refractor that, in theory, should yield sharper images. I sold my EVScope and used the funds to purchase the new Vespera - and a few other things, because wow that price difference is huge. 

These are two approximately 10-minute exposures of the Orion Nebula. Atmospheric transparency and seeing were about average - maybe a little worse than average - while I took the picture on the left. Both conditions were definitely above average while I captured the shot on the right. Believe it or not, Orion was also much higher in the night sky while I took the picture on the right than when I took the image on the left.

Of course, I took the picture on the left with the $1590 Vespera II and its $229 light pollution filter, while I took the image on the right with the EVScope 2, which is now on sale for $4,409. The Vespera focuses itself, but I'd carefully collimated the EVScope before using. I expected a difference in performance, sure, but the magnitude of that difference still astonished me. 

Actually, these pictures do not reveal the biggest distinction between the two images. Because of the Vespera's shorter focal length and more sensitive sensor, its images capture far more of the night sky. In fact, its new "CovalENS" feature allows for the integration of multiple stacked images of adjacent corners of the night sky, which should enable sweeping mosaics of, say, the entire Andromeda Galaxy. And I should emphasize again that the Vespera is much smaller and more portable than the EVScope.

Admittedly, the EVScope comes with a tripod, while the Vespera does not (though again, the Unistellar backpack is much pricier than the one offered by Vespera). And the EVScope does have other advantages over the Vespera. It has an eyepiece, so if you want to use it like a regular telescope, you can. As I've often reported in these pages, the view through the EVScope eyepiece looks better than the pictures, though I suspect this is partly because the image is smaller. Magnifying the image on the bigger screen of a phone - let alone an iPad or laptop - reveals its imperfections.  

The Vespera also looks like something built by Apple, seemingly to appeal to buyers who see Apple as the gold standard for sophisticated, problem-free technology. It's a problem. The telescope's sleek surface is slippery and difficult to handle, especially in the cold. Screwing it into or out of a tripod is frightening. It wobbles dangerously and threatens to plummet to the ground (not a problem with the EVScope). It's also easy to accidentally open the Vespera, since there's nothing to lock the optical tube in place until needed, and the power button is far too easy to activate while holding the telescope. The button shines with a bright blue light when it's on. That will be familiar to users of common consumer products, but any amateur astronomer will tell you that a bright blue light is exactly what you don't want as your eyes adjust to the dark. Unlike the EVScope and other competitors now on the market, in important ways the Vespera prioritizes form over function. 

There's more. Whereas the EVScope has no problem with nearby street lights, the Vespera's lack of a dew shield allows those lights to easily create distortions in the image. Horizontal lines at the top corner of my images, I was told, are the product of a nearby (but not particularly bright) light. The lack of a dew shield is also, of course, a ticket to frustration in cold or humid climates (Washington, DC can be both). Vespera sells a screw-in Hygrometer Sensor - for an extra $119. 

Then there's the lack of citizen science. Unlike Unistellar, Vespera has no fancy partnerships with the big guns in space science. If you want to join my friends at the SETI Institute in searching for exoplanets, you're out of luck. And if you want to help NASA track its spacecraft, stick to the EVScope. 

The biggest problem with the Vespera II, however, is battery life. The EVScope 2 can keep imaging for up to nine hours, and other Unistellar models  do even better. By contrast, the Vespera has four hours of battery life - supposedly. I found that its battery consistently dropped down to 85% capacity after I had set it up, which takes over five minutes (setup was much quicker with the EVScope 2). In subzero temperatures, I suspect I could squeeze about three hours out of the telescope. Storage capacity is also much lower in the Vespera II, compared to the EVScope 2, but to me that doesn't matter; I always move good pictures to my phone's photo album. 

So do the many little shortcomings of the Vespera II, relative to the EVScope 2, overwhelm the advantages of its sharper, bigger, more colorful images, its autofocusing, and its more portable size and weight? The answer is: no, not even close. At present I think the new Vespera is simply a much more capable telescope, and again: it's sold at a fraction of the cost. In fact, I now fear for the future of Unistellar. The likes of Celestron and ZWO are offering telescopes that target both the high and low ends of the smart telescope market. I suspect that, if Unistellar stays in business, it will owe a lot to the connections its founders wisely made with SETI and NASA. 

I should say that I've reached my conclusions primarily by observing the Orion Nebulae. Planetary images, I suspect, are better with the EVScope 2 than the Vespera II, owing in part to the former's greater focal length and aperture. But that's really not why I'd want to use EAA. Even my C90, for example, gives a vastly better view of Jupiter than the EVScope could provide at twenty times the cost. 

Of course, as I've often described in these pages, all smart telescopes have the same shortcoming. To use them you wait around and stare at a screen. There's still something different - something special - about looking through a glass eyepiece instead, at age-old light at it shimmers through our roiling atmosphere. 

Usually, the atmosphere is turbulent during our DC winters, but this winter has been an exception. The reason might have to do with atmospheric circulation rerouted by a particularly intense El Niño, but I'm not sure. In any case, winter has been unusually accommodating for amateur astronomy in the District. Yet I haven't taken out my telescopes, and I haven't updated this blog, because, unfortunately, I've found myself too sick, too overworked, or - most often - both. 

This month has been much better, however, and on the 18th I finally decided to give my kids a view of the halfway-illuminated Moon. I stepped out with what is now my smallest refractor - the Takahashi FC-100DZ - and quickly found atmospheric turbulence to be a little worse than average. That's perfectly okay for a DC winter, and after the telescope cooled down - in about ten minutes - it delivered a very nice view of the Moon.

Unfortunately, when uploaded to this blog the picture looks a bit blurrier than it does on my desktop. But look closely at the center. That's Rupes Recta, a linear fault about two kilometers wide that cuts across some 110 kilometers of the lunar surface. Here it is zoomed in: 

Just below the fault are the craters Birt A and B, named after William Radcliff Birt, a nineteenth-century selenographer. Birt coordinated a network of amateur lunar observers across Britain who all sought to record changes in lunar features, which they thought would reveal the Moon to be a world similar to Earth. It's a story that I'll describe in my next book, Ripples on the Cosmic Ocean. The book is one reason I've been so busy this winter: I've finished a complete draft, and am now revising (partly by shortening). 

In any case, the kids enjoyed the Moon. For them, it's a neat little thing that daddy likes to show off occasionally. Of course, I try to impress them by waxing poetic about the wonder of gazing, from a comfortable little backyard, at the alien peaks and hollows of a whole other world, one utterly different from our own. They're appreciative, but hardly awestruck. I've decided that it's nice that Moongazing is so normal for them. 

The following night was clear again, but a good deal colder. Still, I decided to try my Mewlon 210. After letting it acclimate for about 90 minutes, I walked over to a nearby tennis court and pointed it at the Moon. Once again, I was struck by just how easy the Mewlon is to handle. It's lightweight, and you hold it by the rock-solid finder scope. It's just a wonderfully-crafted hunk of metal and glass. It's hard not to want to use it, if that makes sense. 

When I pointed the Mewlon at the Moon - and yes it's so nice not to have to attach and then align the finder scope - I found it was cooled down and well-collimated. Atmospheric seeing was about average, but the view was quite breathtaking. The terminator had advanced a little beyond my favorite spot on the Moon - the expanse between and around Plato and Copernicus - yet both craters retained a hint of shadow around their rims. The Mewlon gave a three-dimensional quality to the extraordinary complexity of the terrain in this part of the Moon, in particular the mountains and crater rims. 

This time the view was truly sublime. With the Moon near zenith and the atmosphere unusually stable, the fully-acclimated DZ showed off what it can do. The view wasn't as bright as the Mewlon offered on the previous night, but owing to the steady atmosphere they were a bit more detailed. I noticed craterlets on Plato's floor with the Mewlon - a classic test of good seeing and optics - but now, with the DZ, they were more continuously obvious. 

I soaked in the view for a 30, maybe 45 minutes as my fingers slowly froze. I did notice that the view routinely slipped ever so slightly out of focus, owing perhaps to the focuser with the telescope pointed straight up. But wow, that in-focus view was wonderful: among the best I've had of the Moon. I especially enjoyed the lunar maria. The picture above gives a hint of the delicate tendrils I followed across those maria: subtly different shadings, some radiating from brilliant, intricately-detailed craters. 

It was a lot to take in, but my fingers soon convinced me to pack up and head inside. Lunar observing is perhaps overlooked in amateur astronomy, but it truly is an incomparable experience to explore another world while standing within sight of home. 

If November isn't my favorite month to observe here in Washington, DC, it's right up there with March and April. Most nights are cool, crisp, and imbued with an ineffable fragrance - of decaying leaves in autumn, of budding blossoms in spring - that encourages deep breaths. The mosquitoes are resting after (or before) the horrors of summer, and seeing hasn't yet slumped to its winter lows.

I try to use my telescopes as much as I can in late autumn and late spring, but there's a problem: these are the busiest times in the academic calendar, and it's not always easy to juggle my hobby with my work. Worse, both seasons are times of unrelenting illness for any parent with young children. So it is that while the sky has been routinely clear for the last month, with seeing typically average, I haven't had much chance to exploit it.

Finally, on November 13th, I felt just healthy enough to venture outside with my TSA 120. At just before midnight, Jupiter was nearing zenith. Although atmospheric conditions were not exactly ideal, I couldn't pass up the chance to have a look. 

I had let my TSA 120 sit outside for about 45 minutes before using it, and it paid off: while temperatures were no higher than 10 degrees Celsius, the telescope had completely cooled down. Yet when I turned to Jupiter, the planet initially resembled a circle of bubbling milk, surrounded by a smattering of drops (the Galilean moons). Why had I sacrificed sleep for this?

Then, as I considered packing up, the atmosphere abruptly stabilized - and now a staggering wealth of detail shimmered into view. It was fleeting - "revelation peeps," to use a Lowellian term, often are - but it was more than enough to keep me glued to the eyepiece. Over the next hour, belts, zones, and the Great Red Spot all flickered across the pale Jovian disc, and I nearly lost track of time. Finally, it dawned on me that even a bad night's sleep was slipping away, and I hastily carried my equipment inside. 

Perhaps it's a character flaw that I like to obsessively compare my instruments; if so, it is a flaw I share with most amateur astronomers. In this case, I couldn't help but reflect on the TEC 140 I once owned. In a vacuum, I might prefer that telescope over the TSA 120. But the difference in the optical performance of both telescopes is slight enough that I prefer the far greater portability of my TSA 120 setup. It weighs half as much, and that makes it so much easier to use when I'm tired. 

Of course, when it comes to portability and ease of use it's hard to beat my EVScope 2. With Orion starting to rise high above the horizon in the wee hours of the night, I decided to use that telescope to view the constellation's famous nebula. On the 18th I parked the telescope in my backyard, found a gap in the increasingly bare trees, and had a look. 

As usual, within seconds the EVScope delivered a view that no traditional telescope could match under an urban sky. Yet using the telescope so soon after observing with my TSA 120 gave me a clear sense of what bothers me about it. The EVScope is easy. There are no "revelation peeps" - no flashes of transcendence - because everything is smoothed out in a (relatively) pretty picture. There's no craft to observing, no sense of taking in the universe with your own eyes. You see more - but you feel less. 

Sometimes, that's okay. There are whole classes of object - white dwarfs for example - that I can only glimpse with my EVScope (at least in our light-polluted skies). Yet if I were forced to give up one telescope, I would choose the EVScope without a second's hesitation. 

My health improved this week, and my workload (temporarily) eased. Now I steeled myself for a challenge I've dreaded for weeks: collimating my new Mewlon 210. I've been so unwilling to try it that I even - very briefly - placed the telescope for sale. Yet I read up, prepared my Allen key - and left the Mewlon out for an hour to cool down. 

When I returned outside, I found that the telescope still had not completely acclimated to temperatures that were not far above freezing. I waited another half hour, then tried again. Now the telescope seemed cool enough, but to my surprise my first view of a star was so underwhelming that I again considered whether to sell the telescope. A blob is the best I could get - a far cry from the pinpoints I see through my refractors. 

I'd hoped that I'd been wrong about the Mewlon's collimation, but now there was no doubting it: the telescope's secondary mirror simply did not perfectly align with the primary. I set to work tightening bolts, and to my surprise I didn't mind it. Years of tinkering with mechanical watches and bicycles had prepared me well, I suppose, because after 15 largely painless minutes I was just about done. 

I could scarcely believe my eyes when I returned to that star. Instead of a blob, there was a perfect little diamond. To my amazement, the telescope's diffraction spikes - a product of the four vanes that hold its secondary mirror - actually added to the star's beauty. It wasn't perfect - seeing was actually below average - but it was about as beautiful a stellar image as I can remember seeing. 

Jupiter offered some of the same revelation peeps I'd enjoyed with my TSA 120, except with a bit more color (and this time, the diffraction spikes were a bit distracting at lower magnifications). Turning to the Trapezium in Orion clearly revealed five, perhaps six stars - a challenge for fine optics even in good seeing - but it was Betelgeuse that truly stole the show. The star was simply a spectacularly beautiful orange gemstone when viewed through the Mewlon. The telescope's large aperture (compared to my refractors), total lack of false color, and yes, diffraction spikes made me appreciate simple stars as I never have before.

With any luck, I'll use the Mewlon to spend happy hours admiring the double stars that are easily visible in our city. But on this night, it was time to pack up - and to banish all thought of selling the Mewlon. 

It was midnight on September 1st, and the atmosphere was about as good as it gets for stargazing here in Washington, DC. Transparency was high, seeing was great, Saturn was high in the sky and Jupiter was wheeling over the horizon. My had prepared my TEC 140 in the living room, and prepared to haul it outside. I knew I'd have to walk for a few minutes, and I tried to figure out how best to do it. The telescope itself is just over 20 pounds. The DM-6 mount that holds it well? With its extender, also just north of 20 pounds. The Planet tripod that keeps it all stable? Another 27 pounds.

With my eyepieces and including all the cases and bags that house the gear, I was looking at hauling more than 80 pounds. That might have seemed doable were it not for the size everything took up. I simply could imagine no way to drag my gear to my only nearby observing site in fewer than two - possibly three - walks. It had been a long day at work, and I was still tired from recent travels. I left my gear in place. There would be other nights. 

The next morning, it dawned on me that something was out of whack. Since my little backyard faces north and is usually too shrouded by leaves to be useful for astronomy, I need to be able to easily transport my gear to a more suitable spot. Last year I bought a wagon to make that easier, but dragging it around turned out to be nearly as difficult as carrying my equipment. Given my need to walk to observe, I'd long ago decided that my heaviest telescope would be a medium-sized refractor, and the TEC seemed like the best option available. Somehow, however, I'd ended up with a heap of gear that was almost impossibly heavy to walk with. What happened? 

Well, it turns out that in amateur astronomy - as in many other things - a sufficient number of little changes can collectively create a new paradigm. The trouble was that the TEC 140 is just a bit heavier and (especially) longer than a medium-sized mount can handle, and that required a big, hulking DM-6. Both DM-6 and TEC 140 are also just a bit too heavy for a medium-sized tripod, especially on a hard surface. Enter the Planet tripod. A medium-sized telescope therefore required gear that was heavy enough to hold something much larger. Yes, it was beautifully stable once set up. But that didn't mean much if it was too massive to move. 

With a heavy heart, I put my TEC 140 up for sale. Within hours, a friendly local buyer had scooped it up. While I was, on some level, sorry to let it go, it also struck me that I'd made few genuinely special memories with it. I tend to grow attached to instruments that have genuinely shown me something new. My dearly-departed TV 85, for example, revealed just how much sharper a refractor could be in our DC weather than any other kind of telescope - and gave me my first unambiguous view of the Great Red Spot. My Takahashi FC 100DC gave me truly unforgettable views of Mars, and the shadows of Jupiter's moons. My APM 140 gave me even more stunning views of Mars and Jupiter, and then the 100DZ left me breathless while gawking at the Moon. The TEC 140 did give me a wonderful sensational of texture in the Jovian clouds. But that wasn't quite enough to build a bond.  

After I sold my now-useless DM-6 and Planet tripod, I had some decisions to make. Should I downsize by, for example, buying a jewel-like Questar 3.5? I opted it against it after reading convinced me that the iconic little telescope could simply not compete with the also-portable 100DZ. I opted to attempt to buy two lighter but still medium-sized telescopes that I hoped could largely replace - or even improve upon - the capabilities of the TEC, while requiring a much lighter tripod and mount. 

The first of those telescopes: a TSA 120. Takahashi's four-inch refractors have long been my favorite telescopes. I decided to try something a little bigger in the five-inch TSA 120, an air-spaced triplet (a refractor with three lenses) that, I thought, could gather meaningfully more light than the 100 DZ. I'd long resisted buying an air-spaced triplet, since these telescopes weigh more than doublets and take much longer to cool down. The weight of the TSA 120, however, splits the difference between the TEC 140 and 100 DZ, and I figured I could simply let it acclimate in my backyard before carrying it to a more suitable observing site. 

To my delight, I managed to buy the TSA 120 on sale. When it arrived, I was immediately surprised by its compact size. Although its aperture is just a bit lower than that of the TEC 140, its dimensions seem closer to those of the 100DZ than the TEC 140. I also had not expected it to ship with a quality two-speed focuser. You can purchase the telescope with the bulkier but ostensibly more precise Feathertouch focuser, but Takahashi's equivalent is, to my mind, just about as good. Truth be told, I don't really understand the obsession with replacing the focusers on premium telescopes, like the Takahashi refractors. All you need is something that gets the telescope in focus, and to my mind the stock focusers do that very well. 

It's a small point and one I've brought up before, but still: I can't get enough of the Takahashi aesthetic. The white tube, black trim look is classic for a reason, but here's to doing something a little different. I think Ed Ting once mentioned that Takahashi telescopes have an indefinable Zen character to them, and that feels about right. It makes me inexplicably happy to see them. That's not to say that the build quality of the TSA 120 exceeds that of the TEC 140, but I do prefer that cream-colored paint with mint-green accents. 

Anyway, on September 14th the sky cleared and temperatures cooled just after I'd finished setting up my new TSA 120 (with Moonlite tube rings courtesy of a very helpful veteran of the Cloudy Nights forum). By then, I'd found that my Berlebach Uni tripod and (wonderful) NoH's Mount CT-20 easily support the TSA 120, which made for a setup that weighs about 40 pounds total - half as much as the TEC 140 and its equipment! 

I bought a Stellarvue C9S case for the TSA 120 that fits it exceptionally well, and I left the telescope outside, in its case, for about 40 minutes before using it. This time I easily walked to my nearest observing site, in the courtyard of my building. Saturn is just about a month past opposition, and high above the horizon at about 11:00 PM. I decided that its light would be the first that entered my new telescope. 

I have a strange relationship with Saturn. To me, it's still the most impressive object in the night sky. Yet as a target for repeat observation, it pales in comparison to Jupiter and Mars. Its rings change their tilt over time, sure, but I can rarely make out enough detail on its disk to give me the impression that I'm viewing an evolving world.

Well, the TSA 120 might change that. At about 90x with my Delos 10mm eyepiece, Saturn was spectacularly well defined. I'm not sure I've ever seen such fine detail in the grey clouds above its rings. The outline of its rings was razor-sharp, the Cassini division clearly outlined. It was, I decided, about the best view I've had of the planet. Mosquitoes started to emerge, whining near my ears, but I was so distracted that I soon found myself covered in bites. I packed up and walked back home - easily.

When I got inside, I was a little taken aback. I wasn't sure exactly how my view of Saturn compared to the best I had with the TEC 140; almost exactly two years ago I marveled in these pages that the bigger refractor gave me an "absolutely stunning" look at that planet. And yet, I couldn't say while unpacking the TSA 120 that I'd ever had a better view of Saturn. The sharpness is what most impressed, and the collection of bright little moons, swarming around the planet like moths around a lantern. Granted, both seeing and transparency had seemed better than average. But if the TSA 120 gave me a view that left me so satisfied, why had I hauled around so much more weight for so long? 

On September 15th, the pellucid evening sky invited another round with Saturn. This time, I brought out the second telescope I'd purchased: a Mewlon 210. These unusual Dall-Kirkham telescopes are a little like condensed Newtonian reflectors, with very long focal lengths. They cool down more quickly than other catadioptric telescopes - like the ubiquitous Schmidt–Cassegrain - and have none of the dew problems that can hamper these telescopes in a humid environment (Washington, DC certainly qualifies). 

Takahashi makes its Mewlon variants to exacting specifications, and that should in theory make them exceptional planetary telescopes. They are famously tricky to collimate, however, and they must be perfectly collimated to realize their potential. They also take a lot longer to cool down than (smaller) refractors, and their field of view is much narrower. They are much more sensitive to poor or mediocre seeing than those refractors, and the vanes that hold their little secondary mirrors produce faint rays around bright objects. The Mewlon is, therefore, a specialist instrument.

Yet when conditions are right, all Mewlon variants are designed to give spectacular views of the Moon, planets, and double stars: precisely those objects I most enjoy observing in the city. At over eight inches in aperture, in good seeing the Mewlon 210 should in fact reveal those objects with even greater brightness and detail than the TEC 140. And - remarkably - it weighs much less than that telescope, despite looking much heavier. 

On that note, I will add that, in my view, the Mewlon 210 is quite possibly the most impressive amateur telescope to look at. It is simply beautiful. It looks like a jet engine crafted with care by a Swiss clockmaker. What's more, it comes complete with a finder scope that stays perfectly aligned with the telescope, and is so robust that you can use it as a handle. You may have to collimate the telescope from time to time, but you never have to align the finder - and that makes up for a lot. 

So how did the Mewlon perform on Saturn? Sadly: not as good as the TSA 120. It was clear from the box that the telescope had been handled roughly on its way to me, and something - or someone - had knocked it out of collimation. All the same, it was only a little off, and I hope I can tweak it to perfection sometime soon. Maybe in my backyard, after the leaves finally fall? 

Remarkably, atmospheric seeing and transparency were again above average last night, so I stepped out again with my TSA 120. This time, I waited until about midnight, when Jupiter had climbed above the horizon. I turned to Saturn first, and now the view was truly breathtaking: slightly but meaningfully more vivid - more crisp - than I'd seen even a couple nights earlier.

I quickly switched to a 4.5mm Delos, giving me a magnification of exactly 200x. In my experience, Washington's sky rarely allows that kind of power. Yet to my astonishment, the atmosphere repeatedly settled down to allow a remarkably sharp view at that magnification. The subtle mingling of grey, beige, and buttermilk threads in the planet's atmosphere was simply a joy to tease out, and I could make out glimpses of structure in its ring system that I'm not sure I've ever seen before. 

Was this my best-ever view of Saturn? I concluded that it probably was, and again I was so enthralled that I lost track of the mosquitoes biting me. Eventually I wheeled the telescope around to Jupiter, and now the view was a little softer. The planet was still climbing out of (Earth's) thicker atmosphere near the horizon, and seeing seemed less stable in its corner of the sky. Still, I routinely made out wonderfully delicate detail in its many belts and zones. 

It's a little silly to compare the view through different telescopes on different nights, and perhaps sillier still to compare exceptional refractors to one another. Yet even (or perhaps especially) the most unscientific comparisons are fun, and in this case I think they're instructive.

On my nights of observing, I judged that the TSA 120 showed just a bit less contrast - on Jupiter especially - than the TEC 140, and perhaps the APM 140 I once had. Yet it showed more contrast than the 100DZ - the planets seemed just a bit more vibrant - and the views were just as sharp; sharper than anything I could remember seeing through the bigger refractors. I was particularly impressed by how easily the TSA 120 snapped into focus, and how readily it gobbled up magnification. On both fronts, it seemed to exceed the performance of any telescope I've tried using. 

Now, all the usual caveats about the atmosphere certainly apply, but that's the point. When telescopes get to a certain quality and size, it's often factors beyond the performance of their optics that are most important. I truly did love my TEC 140. Yet I can't conclude that it's superior to the TSA 120. Both telescopes have brilliant optics that, in Washington DC, are almost invariably limited by the atmosphere, rather than their innate capabilities. Yet a setup that supports one telescope is fully twice as heavy as the other. When you're tired at the end of a long day, it doesn't take much to discourage even a quick observing session. With that in mind, the lighter, more portable setup is more often the best one. At least, it seems like it is for me. 

I know this is a long entry, but I can't conclude without mentioning a recent trip to the Royal Astronomical Society of Canada archive in Toronto. Since I was last there, the society's staff have set up several dozen telescopes that had me feeling like a kid in a candy store. There were two beautiful Unitron refractors, an exceptionally long Antares achromatic, a huge Cave reflector . . . the list goes on. But one in particular stood out - the ugliest one, by a long shot. 

Yes, that's David Levy's trusty telescope: a makeshift Dobsonian reflector complete with duct tape and what looks like a jar (!) over a finder scope. Plaques commemorating discovered comets line its base like kills on a Spitfire. Here was a poignant reminder that the best telescope - or indeed the best machine of any sort - is the one that works for you, and you alone.