Tonight was one of those relatively rare wintry nights in Washington, DC, where atmospheric transparency is high while seeing is better than average. With Mars just four days away from opposition - its biannual closest approach to Earth - I couldn't let the opportunity slip. The canopies above my backyard are now sufficiently denuded for me to use a telescope just a few steps from my door, so out I stepped with my TEC 140.
The Moon was just about to slip behind my building, and I was hard pressed to get a quick picture. The view was in fact beautifully sharp, what you see above is the only shot I could get. I also managed to get a quick look at Jupiter, where to my surprise it seemed that one moon - near the limb of Jupiter - was far below the orbital plane set by the other moons. I don't think I've seen that before.
Eventually, I found a comfortable nook from which to observe Mars. Seeing seemed a good deal better than average tonight, and the outline of the planet was about as sharp and steady as I've ever seen it. I was struck by how much smaller it seemed than it did during its last opposition, two years ago, when it looked only marginally smaller than it did during its perihelic opposition of 2018. Of course, my gear has improved since then, so the views of Mars I've had this year haven't been much worse than those I had in 2020. Still, the planet's apparent diameter is only about 17 arcseconds this year - down from 22.4 in 2020, and a whopping 24.2 in 2018. In fact, not since 2014 has Mars looked so unimposing at opposition.
More important for viewing Mars than the apparent size of the planet or my equipment, however, has been dust. In 2018, I couldn't make out any details on Mars while using my Skywatcher 100ED, and that owed more to a yellow, planet-wide dust storm than the lack of perfect color correction on the refractor. In 2020, Mars was relatively dust-free, and so a deeper shade of red. I was ready then with a pair of telescopes (my dearly departed APM 140 and Takahashi FC-100DC) that were only slightly less capable than those I own today. Now Mars seems dusty and a bit yellowish again, but not as much as it was in 2018. Surface detail has obvious through my TEC 140 and Takahashi FC-100DZ, though not as much as it was in 2020, and the planet's disk is comparatively small.
I replaced my APM 140 with the TEC 140ED, and my FC-100DC with the FC100DZ, in large part to prepare for this year's opposition. I'm glad I did, but in making those replacements I've also come to realize that there really are rapidly diminishing returns for costly upgrades in this hobby. Yes, views through the DZ seem marginally better than the ones I enjoyed with my wonderful DC, but from night to night conditions in our atmosphere - and that of Mars - are much more important.
Tonight I was again reminded of how trifling differences in performance between optics can be enormously exaggerated in online discussions. It's widely held that high-contrast eyepieces such as the TeleVue Delos will easily outperform zoom eyepieces, including the latest iteration of the Baader Hyperion Zoom. While switching between the zoom eyepiece and the Delos 4.5mm and 6mm eyepieces, however, I found that magnification affected the view far more than the eyepiece I was using.
The view seemed just right at around 160x; any more than that, and it got a little blurry. Both the Baader and TeleVue eyepieces provided striking and at times rather complex views of Mare Cimmerium at that magnification, along with flashes of Trivium Charontis and perhaps some other dark regions in the northern hemisphere of Mars. I thought I might have caught some hints of white swaths far to the south, but they were hard to pin down; I fancied they might be clouds.
I saw very little to separate the eyepieces, but I eventually found myself settling with the 6mm Delos because of its larger field of view. If pressed I might confess that dark albedo regions were more consistently obvious in the Delos than the Baader Zoom - but that may be only because I expected to see them more clearly in the Delos. One thing's for sure: I'll never again assume that I'm missing out by using the zoom eyepiece as opposed to a Delos, and I'll be a little more careful when reading claims that one premium eyepiece or telescope is clearly superior to another.
I hope to have another chance to observe Mars this week, and certainly this month, but if not tonight was a wonderful way to mark the planet's opposition.
Autumn came early this year in Washington DC, yet the relative warmth of early autumn lingered well past its usual expiration date. The mosquitoes lingered with it, even if their population fell with the leaves, but overall it's been a gorgeous month in the city. Over the past week, we had three crisp, clear nights with tolerably good seeing and transparency. With the canopies above my yard increasingly bare, I was able to peak through and branches and observe without hauling heavy gear for twenty exhausting minutes.
A few nights ago, I rolled out my TEC 140 to observe the Moon and Jupiter. Night comes early at this time of the year, of course, so I made it outside before my six-year-old daughter's bedtime. I asked her to join me, and when she did she was thrilled to make out craters on the Moon and, with some difficulty, cloud bands on Jupiter. To my surprise, those were unusually difficult to make out. The sky had a milky quality around bright objects, a kind of watercolor softness, that seemed to obscure detail on the likes of Jupiter. Still, a memorable experience for daughter and daddy alike.
On November 8th, conditions promised to be marginally better, and temperatures were just about ideal. This time, I stepped out with a much lighter setup: my Takahashi FC-100DZ, clamped to the CT-20 mount that I'd screwed into my Berlebach Uni tripod. It's a more robust outfit than I take to the local park, but it's still easy to move all in one go.
A quick aside: the exceptional weight of the DM-6 mount can make it really sturdy and capable of handling surprisingly hefty telescopes. Yet it also ruins the portability of my TEC 140. The mount feels at least as heavy as the telescope, and when yoked to a tripod it's a chore to move even without the telescope attached. Another problem is that attaching the telescope to the DM-6 mount is a heart-stopping experience in the dark. It's hard to be sure that the dovetail is actually in the clamp, and I've now been unpleasantly surprised several times when the telescope suddenly lurched down after I thought I'd got it in. I live in fear that on some sad night I'll misjudge it, step away, and watch in horror as the telescope crashes to the ground.
I have no such problem with the Takahashi. Yet the lightness of the CT-20 mount does mean that the telescope tends to tilt - even when perfectly balanced - if objects are too close to zenith. The CT-20 has an answer, however: it's easy to adjust the tension in the altitude and azimuth axes. This can mean that there's too much tension to easily nudge the telescope along when observing objects that are high up in the sky, but I'll take the tradeoff: less weight and less hassle is worth some compromise.
In any case, the Takahashi gave me some very satisfactory views of the waning but still nearly full Moon. The view along the emerging terminator in particular was quite striking, while the Moon's fully illuminated surface showed a mesmerizing swirl of subtle grey shadings. The rays streaking from Tycho, one of the youngest big craters on the lunar surface, are always impressive when the Moon is this close to full.
Yet Mars is now wheeling towards its biannual opposition, so of course it stole the show. The planet is quite high in the sky by around 10 PM EST, and it's already brighter than any celestial body visible at that time save Jupiter and the Moon. I feel that its color even by naked eye is not quite as blood-red as it was two years ago; it's paler and a little closer to orange.
The Takahashi revealed its waxing globe, but showed considerably less contrast than I could make out a couple years back. In moments of good seeing I could make out the south polar icecap, and then a dark albedo swirl around the ice, interrupted by lighter land before continuing towards the north. Yet the view was anything but sharp, and the planet seemed unsteady somehow in the mediocre seeing. Part of the problem is that much of Mars is currently obscured by bright dust storm: a common if frustrating occurrence when Mars makes a close approach to the Sun.
It was to gain a clearer view of the Moon and Mars that I stepped out last night with the TEC 140. Conditions seemed about the same, except it was colder and the reappearance of a halo around the Moon suggested that transparency would be lower. The TEC takes meaningly longer to cool down than the Takahashi, although in both cases the Delos eyepieces take longer to acclimate than the telescopes. I'm not sure it's widely understood that compound eyepieces take longer to cool down than, say, Plossl eyepieces - but that's certainly been my experience, and it does stand to reason. There's just a lot of glass in those things.
In any case, both refractors and their eyepieces need only a few minutes to give acceptable views, even if they do take longer to fully acclimate. When everything was ready I was surprised to find that the TEC 140 actually provided slightly softer views than the Takahashi did the other night, even if contrast on Mars in particular seemed just a bit higher, and the Moon's terminator at times snapped into exquisite if fleeting focus. I was once again impressed by the Takahashi; despite its compact size, I rarely feel I'm missing out when I use that telescope, the way I did with many other small telescopes I've owned. It punches far above it weight.
Yet to me the bigger takeaway was that the difference between telescopes is often completely swamped by atmospheric conditions. In mediocre seeing and transparency, there really isn't much of a divide between the $8000 (!) TEC 140 and the $3000 Takahashi (of course both telescopes have world-class optics; even in bad seeing, I would suspect a meaningful difference between them and a run-of-the-mill refractor). In my years of observing here in DC, I can probably count on one hand the nights on which the atmosphere was so stable and clear that I could use magnifications of 200x or more. The pricey difference between optics is often less apparent here than it would be elsewhere, and I think that's something observers should acknowledge more often. Where you live will dictate the gains you get by spending more on bigger and fancier telescopes.
William Sheehan - who publishes some of the most engaging books on the history and practice of planetary and lunar observing - writes that as an observer views Mars near opposition, "over it, intermittently, uncertain details dart and then are gone like doubtful visions." None other than Percival Lowell - a key popularizer of the Mars canal theory, among other things - coined the term "revelation peeps" to describe these sudden glimpses of intricate detail.
That is precisely what Mars had on offer tonight. It wobbled and wavered, like a coin seen through the burbling water of a fountain. Then, for fractions of a second, it snapped into sharp relief, looking really and truly like a planet seen from an approaching spaceship. Just before my brain could grapple with that new reality, the planet reverted so quickly to an indistinct blob that I could scarcely believe it had ever been otherwise.
Mars! Always so difficult, but oh so compelling.
Earlier this month, I set forth on a night of above-average seeing to the field that has become my favorite observing spot, just an eight minutes' walk from our new home. I heaved up the hill bordering the field, hauling my Takahashi and an uncomfortably heavy backpack, full of expectations. As I rounded the top of the hill, I saw . . . this.
It's one thing to install new lights, but these were about the brightest I've seen in Washington, DC. I could scarcely believe my now not-at-all dark adapted eyes. Another observing spot - my third, since this blog began - ruined by newly installed, fluorescent lighting. It's demoralizing to experience firsthand how every patch of dark sky in the city is steadily being surrounded and at last consumed by unnecessary light.
I wandered home, too stunned, too sore, and too tired to find another location to set up. In the days that followed, I reviewed my options. I wandered around my home, and found another location, in a neighborhood garden, just a bit farther than the field - but a lot more overgrown with bushes and trees, and no doubt overrun by summer bugs. Then there was another field, perhaps a 20-minute walk away, and (for now) dark at night.
Wherever I went, it would be farther: and I had trouble enough walking the eight minutes to the now unusable field. I decided I had to reduce the weight of my grab-and-go setup, and in particular ease the strain on my shoulders. But how? MY DM-4, I thought, was about the lightest mount I could use with my Takahashi FC-100DZ.
I agonized over whether to exchange the telescope for something smaller and less capable. I bought it in the first place because it was the biggest and best telescope - that cooled down quickly and provided spectacular lunar and planetary views - I could easily walk with for 10 or 15 minutes. But 20 minutes? And with the mount I needed, and my eyepieces?
Eventually I figured that the step down to something smaller - a Takahashi FC-76 DCU, for example - was just too big a fall to be worthwhile. Since my tripod is already wonderfully light, I was left with my eyepieces and mount. The eyepiece problem was easy to solve. Rather than carry four Delos eyepieces, I decided to take just one eyepiece with me: a Baader Mark IV Variable Zoo. When equipped with its barlow lens, it would give me all the magnification I could want. There was a cost: a marginal loss in sharpness, perhaps, and a meaningful loss in field of view (which means something with a manual mount). Still, I found it a small price to pay compared to the alternative (swapping telescopes).
I also started researching mounts. Readers will know I settled on the DM-4 after using an AYO II mount. Both mounts are impressive. The AYO II is lighter than the DM-4 and more compact, even as it seemed less durable. Now I wondered whether to exchange the DM-4 for another AYO II; weight, it seemed to me, had to come first.
However, I soon found some intriguing newcomers in the quality manual mount market. One in particular stood out: the CT-20 by NoH's Mount, a little company owned by an independent craftsman in South Korea. On paper, the CT-20 weighed less than half as much as the DM-4 (and a third less than the AYO II), while being more compact than both. It cost less and handled more weight. It seemed almost too good to be true - but I bought it, and sold the DM-4.
To my surprise, on the night the CT-20 arrived from South Korea, the sky was clear and both seeing and transparency were well above average. I greedily unpacked the little mount, hoping I'd be able to use it immediately. I was immediately impressed - and, to be honest, a little surprised - to find that its build quality seemed exceptionally high, on par certainly with the AYO II and DM-4. I was also delighted to find that the mount is even more compact than I'd expected (this is a rarity in amateur astronomy, where things tend to be much bigger than you thought they'd be).
This time I packed my mount and eyepiece into a much smaller, more comfortable backpack; all in all, I think I shaved about ten pounds from the load I had to carry. I walked the 20 minutes to the more distant field, and was delighted to find that I still had some energy left - and that the field was mercifully dark. I unpacked, set up, and to my astonishment soon found the mount at least as stable with the Takahashi as the DM-4 - and that without the vibration suppression pads that I used with the bigger mount! It also allowed my telescope to easily clear my tripod; with the DM-4, I'd needed a ($250!) tripod extender for that.
I quickly slewed to the Moon, and there encountered another surprise: a stunningly sharp view of the lunar terminator in the best seeing I've experienced all year. The mountains on the lunar terminator in particular took on a gloriously three-dimensional character, and I easily made out countless subtle rilles and scarps. Rupes Recta, the so-called "Straight Wall" of the Moon, was perfectly illuminated and a particularly striking sight. I got a genuine sense - maybe for the first time - of how eighteenth- and nineteenth-century astronomers could have mistaken rectilinear features on the Moon for signs of intelligent life. I'm not sure a Delos eyepiece would have afforded a better view; in fact, I couldn't imagine a better view.
Next up was Jupiter, and wow: what a sight. I have never - not even with my TEC 140 - seen the planet's Galilean moons look so clearly like colorful discs: like perfect little worlds, clearly distinct from stars. The planet's cloud belts and zones were phenomenally complex, with countless delicate filaments intruding from the dark belts onto the milky-white zones. The planet's southern hemisphere in particular boiled with complexity, especially in moments of seeing so good that the terrestrial atmosphere seemed simply to disappear.
I observed the planet for a long time, spellbound. It was thrilling not only to feel so close to that alien world, but also to know what the Takahashi (and my entire grab-and-go kit) is really capable of. Then a sprinkler went off in the distance. It was too far to worry me - until I realized that another sprinkler could well be waiting under my feet. I quickly packed up and made my way back home.
I'll come back to that field, sprinklers and all - but now other locations seem in reach, thanks to an unheralded little mount that may just be the best I've ever used.
Binoculars have long frustrated me. While I've thrilled at catching glimpses of rocket launches or lunar craters with big Celestron binoculars here in Washington, DC, I could never hold them steady enough to make out more than blurry glimpses. I opted for more manageable binoculars, but still: no matter what I did, the view was always disappointing. Eventually I gave up and decided that binoculars were just not for me.
Then I learned about image stabilized binoculars: remarkable little devices that use gyroscopes and moveable lenses to cancel the inevitable vibrations caused by human hands. The high cost and relatively small size of these binoculars at first convinced me that it just wouldn't be worth it to buy one. Eventually, however, I found that I'd accumulated a heap of eyepieces I no longer used, and after selling them I took the plunge. I bought a pair of Canon 12x36 Image Stabilization III binoculars.
When they arrived, I decided to try them out on the abundant birds in my backyard. I'm not a bird watcher - the one time I went on a bird watching tour at a conference, I was nearly abandoned in the middle of a desert - but I have to say, I was absolutely floored by the view. It really felt like the bird I was looking at - a female cardinal high up in the canopy - was right there in front of me on the table. The view was absolutely crisp, razor-sharp with no false color, and better yet: it was stable. It's hard to emphasize enough what a difference that makes.
I was eager to see what I could make out on the planets, which had become very prominent in the mornings. When I tried, however, I was disappointed. This time I noticed some false color, and the image wasn't quite sharp enough for me. I figured, sadly, that even the best binoculars might not have much value for me in astronomy.
Yet last night I couldn't resist the temptation to try out the binoculars one more time. The last "supermoon" of the year was rising, the Perseid meteor shower was peaking, and I really wanted to go to my favorite park. It's a long and painful hike with a telescope, but easy and fun while riding a scooter with one-pound binoculars in a backpack. I zipped out at around 11 PM, and made it to the park in no time.
The very first thing I saw as I reached my preferred observing spot was a bright meteor: an auspicious start if ever there was one. When I looked at the huge, golden Moon, however, I was again disappointed: it was just a bit blurry, with too much false color. This time I carefully adjusted the binocular's collimation and focus, waited a few minutes for it to acclimate, and tried again.
What a difference! Now the Moon was wonderfully sharp - like those birds in my backyard - and to my astonishment the view really wasn't much less impressive than it is with my Takahashi refractor at low magnifications. The amount of detail I could make out was nothing short of miraculous. Then I turned to Saturn, and could hardly believe it when I easily made out its rings. Jupiter was rising above the horizon, and sure enough: there were its moons, perfectly clear in binoculars with an aperture of just 36mm.
There was something exhilarating about how easy it all was. The binoculars are little bigger than my hand, and of course they required essentially no setup. But there I was, with bats fluttering overhead (I saw one through the binoculars), admiring the heavens. After about 15 minutes, I had that giddy feeling I sometimes get during my best nights under the stars - and since I wanted to leave on a high note, I hopped back on my scooter and sped home.
Image-stabilized binoculars cost a lot more than a decent pair of regular binoculars (but a lot less than premium binoculars with high-quality optics). However, I'm now convinced that it's difficult to compare them to their lower-tech cousins. It's a completely different experience to use them. Because their views are stable, looking through them is more like using a telescope than regular binoculars - with the added benefit of the three-dimensional experience that binoculars (or binoviewers) uniquely provide.
I have a real weakness for little instruments that provide outsized views (it's why I loved my TV 85 as much as I did). After last night, I have to conclude that the diminutive Canon 12x36 is, quite possibly, the most impressive optical instrument I've ever tried out. It doesn't often work out this way in amateur astronomy, but sometimes big things really do come in little packages.
Here in DC, it's hard to avoid thinking obsessively about the demoralizing news from eastern Europe. Yet the skies cleared recently, enough for an hour or two of late-night escapism. A few nights ago, I slipped out with the Takahashi. Transparency was really good but seeing was far worse than average, and since it was well below freezing I didn't want to stay out for long. Still, the FC-100DZ performs so well in poor seeing that I still managed to have a nice view of the waning Moon from my new backyard.
Conditions were similar last night, with good transparency and poor seeing. By 10 PM the Moon was only just beginning to rise, which means that the sky was still quite dark. The Big Dipper was climbing towards zenith, and that gave me a chance to image Bode's Galaxy - M81 - with the EVScope 2.
I tried imaging M81 with the EVScope 1 on several occasions last year. I have a particular fascination for barred spiral galaxies like M81, which at 12 million light years away is a little smaller than our galaxy. I'm not sure where that comes from exactly, though the shape is certainly aesthetically pleasing. As a kid, I vividly remember admiring a picture of a barred spiral - was it NGC 1300? - that really captured my imagination. Then I found out, when I was a little older, that our own Milky Way was actually a barred spiral, not the conventional spiral it's usually portrayed to be. That was a fun little eye-opener for me.
In any case, observing Bode's Galaxy with the EVScope 1 was a disappointment for me. The galactic nucleus is bright enough, but the spiral arms are subtle and easily lost in the downtown DC light pollution. I never got much more than a blurry circle. The EVScope 2 allows me to take longer exposures, however, and that plus its higher resolution made me hopeful of a better outcome last night.
And indeed, this is far better than anything I managed with the EVScope 1. To capture this 26-minute exposure from my backyard in downtown DC, after just a few seconds of setup time, seemed borderline miraculous to me. This time, I also peered through the new and improved eyepiece of the EVScope 2. What a huge improvement! Looking through the eyepiece of the original EVScope was like looking down through a barrel at a tiny, pixelated square. But the eyepiece of the EVScope 2 feels like . . . well, a proper eyepiece. The view is circular, it feels close, and it's noticeably higher resolution. In fact, it looks more impressive than the image above.
The gallery above shows the difference between unprocessed 9-minute, 18-minute, and 26-minute exposures. The difference is subtle, but it adds up. Note the relative lack of a diffuse glow around the galaxy. With the EVScope 1, that glow used to creep into my exposures after a few minutes, as a result of light pollution here in DC. That's one reason that my views were so much better out of the city. The EVScope is much better at filtering out light pollution, which makes it a far more capable telescope for deep space observing in the city.
When I ranked the telescopes I'd owned last September, the EVScope 1 came it at number 7. I'd rank the EVScope 2 a good deal higher - definitely in the top five, maybe even the top three. It's that good.
With a backyard, I'm able to do something I don't think I've ever tried before: observe the Moon before sunset. I just could never imagine doing that in my old home. On my former rooftop, I might have been besieged by my neighbors, and in a nearby park, hounded by dogs. But now, at last, I can relax behind a fence, set up a nice refractor, and enjoy the Moon at my leisure with a beer in hand. It's beautiful.
During my move, I'd noticed that the focuser on my Takahashi FC-100DZ had a little too much give. The culprit, I realized, was a loose screw. Repairing this little issue led me to consider upgrading other aspects of my grab-and-go setup. I parked the telescope inside to attempt to quantify the vibrations I'd long experienced with the Berlebach Report tripod I'd been using. It didn't take me long to realize that, even in a completely wind-free environment, those vibrations were intolerable at high magnifications.
I will still need to walk to the parks I've often frequented - my little backyard only reveals so much, and the pockets of sky I can access will close when the trees regain their leaves - so I started wondering: did I need to sell the DZ for a lighter telescope? I hated the idea, but I certainly don't want to haul around the tripod I use with my TEC 140 just to use a four-inch refractor. Uncharacteristically, I wrote a note asking the CloudyNights community for help, and help I received.
Carbon fibre mounts, some of the responses stressed, could yield fewer vibrations than my wooden mount. This seemed counterintuitive to me - wood, I thought, tends to dampen vibrations - but I went ahead and purchased an Innorel RT90c Carbon Fiber Tripod. I was skeptical, but sure enough: the tripod just about halved the vibrations I'd experienced. It's also much lighter and more compact, meaning that I now have a more portable and more stable grab-and-go setup. Best of all, I get to keep the DZ: a telescope I love.
I took the above picture of the waxing Moon a couple days ago (February 9th), at around 5:00 PM. At the time, seeing was worse than average, but transparency quite good. Note how much lunar detail the FC-100DZ reveal in even poor seeing; it's quite remarkable.
Observing at 5 PM gave me a chance to, at long last, share my passion with my kids. My eldest is 5, my youngest 2. Both insisted that they could see craters, though my daughter claimed that the Delos eyepiece was a little hard to use. And it's true: it takes a little practice to know where exactly you should position your eye with a big, complex eyepiece like that. I wonder whether a simple Plossl eyepiece would be a better bet for the kids - and for outreach more broadly. It's what's I use with my students (admittedly, partly because I don't want to risk my pricier eyepieces).
It clouded over that night, unfortunately, so I wasn't able to observe after sunset. Yet when I stepped outside the next night to get some air, I realized to my surprise that I could see the Moon setting in the west behind my building. Clouds were rushing in, and the temperature was falling fast. Before my move, I would never have observed in those conditions. Yet now it took me all of three minutes to pop inside, grab my Takahashi, and set up everything up in the only corner of my backyard that still afforded a view of the Moon.
Neither the telescope nor my eyepiece had cooled down, and seeing was atrocious: about as bad as it gets in DC. But as the picture reveals, there was still plenty of lunar detail to be seen. The Takahashi excels in good seeing, but I've also found - like others - that it manages to outperform just about any comparable telescope in poor conditions.
I'm hopeful that, in late fall, winter, and early spring, I'll be able to use my backyard to study the Moon far more consistently than I ever have before. In that effort, I suspect the FC-100DZ will be my most important tool.
It's really hard to beat autumn in DC, and I'm trying my best to take advantage of every clear night. When conditions took a turn for the better tonight, I hurried out, Takahashi in hand, to the nearby park. Some kids were playing hide-and-seek nearby with flashlights - not exactly what you want when you're tired from playing with your own small children - but I didn't need dark-adapted eyes. I was out early enough to observe the waxing Moon and nearby Jupiter. I thought I'd already had the year's last glimpse of Jupiter; now I was determined to have one more look.
Jupiter was low enough in the sky to be tinted red by the thickening atmosphere, and in that corner of the sky seeing was mediocre at best. Still: I could clearly make out ruddy Io, just coming out from Jupiter's disk, with its shadow still on the planet. I couldn't believe my luck. I was able to observe such shadow transits for the first time last year, but I never had the chance this year - until the very last night I could view the planet.
The seeing wasn't good enough to reward prolonged study of Jupiter - and, to be honest, my much bigger TEC 140 has spoiled me a little with its more colorful and textured views of the planet. So I turned to the Moon, then illuminated perfectly around my favorite corner of the lunar surface: the area between the giant craters Plato and Copernicus.
Tonight I was especially struck by the length of the shadows in Plato, which are caused by the crater's mountainous rim. The shadows seem to be caused by mountains that must be higher and steeper than any on Earth. No wonder the Moon was widely considered before the Space Age to be a world of soaring mountains with the proportions of stalagmites in caves.
While the rim of Plato is lined with jagged peaks - remarkable, given that they're nearly four billion years old and would be ground to dust on Earth - they rise "only" around two kilometers above the lunar surface. That's far lower, of course, than Earth's tallest mountains. It's the low elevation of the Sun above the surface that casts shadows long enough to extend the entire 100-kilometer width of the crater. Some nineteenth-century astronomers thought those shadows flickered and thereby betrayed the presence of a lunar atmosphere; not the case, of course.
As I was disassembling the telescope, I happened to look up just as a fireball briefly illuminated the sky: a meteor quite possibly older even than Plato. It was a marvelous sight. I'm continually amazed at what you see just with the naked eye, if you take the time to occasionally glance at the night sky.
One last word on equipment. The Takahashi is beautiful and its optical quality is absolutely top notch, of course, but mechanically it is definitely a step below the TEC 140. The focuser and sliding dew shield, in particular, are just not quite as smooth and solid. I don't know that there's anything I'd change about the TEC, but the Takahashi has a few quirks here and there that I might address if given a chance. Still, it's a little powerhouse and once again acquitted itself well tonight.
We've had a few clear nights this week, with seeing and transparency both hovering near average. It's been a demanding month at work, but I had to step out last night, Takahashi in hand, to catch a glimpse of Jupiter and Saturn. The glare of the rising full Moon, however, discouraged me from going to the park near my house - it would just be too bright, I thought - so I popped up to my rooftop for a quick look.
That rooftop really isn't suited for serious observing. Somehow the concrete slabs thrum with vibrations from my building, and the warm air boiling from the rooftop always worsens the seeing, sometimes dramatically. Nevertheless I did steal a few clear, stable glimpses of Jupiter and Saturn: enough to make out countless zones and bands on Jupiter, and the Cassini Division on Saturn. The small, orange disk of volcanic Io, I believe, was just about to move across the Jovian clouds; I've been so overworked lately that I didn't bother to check.
Then I looked over at the Moon, still rising in the east. Like most observers, I always prefer the Moon when it's only partly illuminated - I love the shadows along craters and mountains - and in any case tonight it was clear that the atmosphere along the eastern horizon was just not going to cooperate. Seeing and transparency in that corner of the sky, it seemed, were particularly challenging. Still, the Moon is always - always - a striking sight through a fine refractor, no matter the state of the atmosphere.
After about fifteen minutes, I packed up and stepped back inside, thoroughly pleased that I'd ventured out despite my fatigue. It's almost always like that: even when tired, there are few things I'd rather do.
We've had some wonderfully clear, autumnal nights over the past week, with Jupiter and Saturn riding high in the evening sky and the Moon waxing and waning nearby. I'm teaching what may be my favorite course at the moment - about the human history of nearby celestial bodies (what I call "neighboring worlds"), and a special highlight is taking my students out for a night with a telescope.
I have now accumulated some very fine refractors, however, and I worried about how they'd fare after being handled by twenty students. To that end, I drew on my research funds to buy a William Optics Zenithstar 81. It's a beautiful little refractor, and I figured that it would be more than adequate to give my students an impressive view of the Moon. For their first assignment, they need to find a feature on the Moon and then write a history of how people have understood, imagined, explored, or planned to exploit that feature.
A few things immediately struck me about the Zenithstar. First, it costs about a third as much as the TeleVue 85 I used to own - less than a third, when you consider it comes with its own mounting rings, dovetail, Bahtinov mask, and carrying case - despite giving up only four millimeters in aperture. Second, its build quality looks to be on par with the very best telescopes I own and have owned, with the possible exception of my TEC 140. Third, it seems to weigh less than the FS-60Q I once owned, and much less than the TV 85, and its sliding dew shield makes it much more compact than either telescope.
It was really easy to carry the telescope to a darker corner of campus, and there set it up on my DM-4 mount and Berlebach Report tripod. Almost immediately, the Plossl eyepieces I'd decided to use provided beautifully crisp views of the nearly fully illuminated Moon. The students who had started to gather were predictably impressed. When we found we had a few minutes to spare at the end of the evening, I decided to try showing them Jupiter and Saturn. At about 56x, the planets were small, but beautifully sharp and clear. Many of my students were awestruck; they had a hard time believing that they could really see the major cloud belts of Jupiter and the rings of Saturn from downtown DC.
Experiential learning is always special; it makes the otherwise abstract concepts we discuss in class come alive for my students, and it can provide lifelong memories. I for one was stunned by the performance of the little refractor. It is, by far, the most portable telescope I've owned, and when it comes to performance it really doesn't give up much to the TV 85. I loved my TV 85, but I would have a hard time recommending that telescope as a go-to instrument when the Zenithstar seems to provide so much more value for the cost.
Last night conditions were even better, and now I resolved to head out with my biggest telescope: the TEC 140. The weight of the telescope, tripod, and mount means that I really can't haul everything to my favorite field. I targeted the little alcove next to a church that I've used over the past year, yet when I arrived as I was dismayed to find that the church had installed a new streetlight that completely ruled out observing there. I wandered about, dragging my heavy gear, until I decided to head down to a little amphitheater near the National Cathedral. There I found a perch that, if I moved around a bit, afforded me a view of Jupiter, Saturn, and the Moon through the canopies of nearby trees.
When I swung the TEC to Saturn, I was mesmerized. This was only the second time I'd used the TEC, and the first time in good seeing. In those conditions, Saturn looked absolutely stunning, like a beautiful jewel set in a velvet background. Its many moons were brilliant and sharp, and the shadow of the planet on its rings gave me the rare sense that I was actually seeing a world in three dimensions (often, objects in the eyepiece look flat, and therefore two dimensional). Cloud details were obvious on the planet's yellow-white disk.
Switching over to Jupiter provided an even more spectacular revelation. The TEC provided what may have been my best-ever view of the planet, with more cloud belts and zones than I could count, delicate, feathery structures within those belts and zones, and a perfectly obvious, brown "barge" - an elongated, oval cloud feature - near the planet's equator. There was a contrast and vibrance to the planet's colors that you just don't get with a smaller refractor, and all four Galilean moons were visible as clear disks, rather than points of light.
Jupiter and Saturn soon wheeled behind the trees, so it was time for the waning gibbous Moon. Once again, I was dumbstruck. The Moon wasn't that far above the horizon, but at 163x there was just such a wealth of subtle, perfectly sharp detail, from jumbled crater peaks to winding rilles and delicate scarps. The terminator was perfectly positioned to throw mountain after mountain in sharp relief, and in exploring them I eventually lost track of time. Then a giant cricket jumped on my pants, I realized in shaking it off that it was past midnight, and I began packing up for the painful trek home.
The TEC 140, I have to say, is noticeably better than the APM 140 I've also raved about in these pages. I'm not sure it's worth the extra cost; certainly I could never have afforded the difference if I didn't use the telescope for my research and writing (which means I could draw from my research funds to buy it). I realize how lucky I am, and I hope I can keep using the telescope for a lifetime.
It won't be that often, however, until I manage to own a backyard; as wonderful as the telescope may be, it's also hard to transport more than a few minutes from our home.
After a surprisingly cool spring (in the context of global warming), it's finally getting hot here in Washington, DC, and with summer comes better seeing. It promised to be above average on the night of the 18th. As Brood X cicadas burrowed out of the ground all around me, I walked over to my nearby church, refractor in hand. I might have been tempted to take the TEC 140 had that not been such a chore last time I stepped out, and anyway all I really wanted was a nice look at the setting Moon. The Takahashi was an easy choice.
It never ceases to amaze me, the endless varieties of turbulence that the atmosphere has to offer. After turning to the Moon, it was clear to me that if seeing was better than average, it would also preclude really detailed iPhone pictures. There was an undulating quality about the atmosphere. Parts of the moon would roll about, as if under waves lazily passing on their way to shore. While it was easy enough for me to see, with great clarity, what was underneath those waves, I knew that my phone would blur the slowly changing view.
Still, what a view it was! At low magnifications - 46x, with a Delos eyepiece - I couldn't notice the waviness of the atmosphere, and the detail was absolutely staggering. The Moon had a three-dimensional quality, and with almost zero false color I could just about make up the subtle shadings and - I thought - differences in color across the lunar surface. It's hard to describe, but the Moon looked likely a rich and fully realized world through the eyepiece - and I could almost pretend that I was somewhere in its orbit. Clearly visible earthshine on the otherwise unilluminated half of the Moon only added to the effect.
When I increased the magnification - up to 177x, sticking with Delos eyepieces - the view stayed sharp, but those remarkable differences in tint and hue were far less obvious, and turbulence detracted from that spacewalk effect. I took some pictures anyway, and what sticks out to me is that those different colorations are just about visible in them: a testament to the superb color correction of the FC-100DZ.
After about 45 minutes, the rustling around me became impossible to ignore - was it rabbits, or something else? - and I packed up, content with yet another breathtaking expedition to the Moon, courtesy of the Takahashi.