 The 24-inch Clark refractor at Lowell Observatory. 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.  The refractor at night. The staff, mostly students, educate the public with great enthusiasm. 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 is quite remarkable, given the size of the telescope. Indeed the air seemed unusually steady, as Lowell had often insisted. My tripod, however, was totally inadequate for the 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.  The AT72EDII. An impressive little instrument on a horrible (but portable) tripod. 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, when mounted atop Mars Hill it might have been the best planetary and lunar telescope in the world. 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.  Telescopes arrayed on the summit of Mars Hill, but yes this is a bad picture. 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 merely 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. 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.  Meteor Crater. I'll long remember sitting on its rim, relaxing while taking in its sublime grandeur. 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.  The wooden construction of the dome is truly impressive and unique. 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.  There is something melancholic about this little monument, with the sadly mistaken quotes adorning its entrance. 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 the refractors usually outperform much bigger SCTs - at least on planets, the Moon, and double stars. If I'm honest, it's rarely close.  Look at those prominences and sunspots! I'm not sure that I've observed such an active Sun. 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.
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