We're less than two months away from Mars reaching opposition, and the red planet is getting awfully bright in the morning sky. Its apparent size is getting pretty big, too, and there are - as yet - no signs of the planetary dust storm that made it so much harder to see details on the planet during its last opposition, in 2018. Now is the time to observe Mars, and with that in mind I dragged my APM 140 out of the apartment and down to the park at 3:30 this morning.
Wispy cirrus clouds were starting to advance from the west as I set up my telescope, and there was an odd haze in the air. Street lamps were surrounded with halos that took on an odd fractal pattern I'm not sure I've seen before. After I started observing, I noticed the same thing around Mars. Oh well! The planet was spectacular nonetheless. The clouds that constitute its south polar hood appear to have broken up as the southern hemisphere enters summer, and the ice cap - now clearly visible - seems quite small. I could plainly make out an an intricate latticework of dark albedo markings stretching up from the pole, covering maybe half the planet's surface. Tonight, the atmosphere allowed me to reach around 170x before the view got a little mushy, and at that magnification the planet is still quite small. Easily big enough, however, to discern a whole lot of detail. Venus had climbed fairly high above the horizon by around 4 AM, and wow did it look weird with the naked eye: squashed into a fat little triangle by those strange atmospheric conditions. It was hazy and painfully bright through the telescope, though still satisfying to see the planet, from our perspective halfway illuminated. I thought I could make out some detail in the planet's clouds around its terminator, near the equator, but seeing was bad enough to make me question that observation. The Pleiades, meanwhile, had also wheeled into view, and I had my first look at them with the APM. Naturally the view was brighter than I've had before, though I wished for a wide field eyepiece - I'd left my 55mm Plossl at home - and the seeing was bad enough to mar the view ever so slightly. Still an impressive sight, however. Once again, telescope, mount, and tripod all functioned exceptionally well. I'm impressed at how easily the lightweight AYO II handles the big refractor when everything is properly balanced. Bizarrely, the telescope handles more smoothly and easily than the Takahashi FC-100DC on the same mount - or maybe it just seems that way, since it takes a little more effort to use the smaller telescope's focuser (it's one-speed only). Certainly the APM is my favorite telescope to use, with the little TeleVue a close second (it would be first, but that big aperture is hard to resist).
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I was quite tired after I last published on this blog, but the night of the tenth was clear again - and again the seeing promised to be better than average. With a week of uninterrupted rain coming our way, I had to step out again. This time I decided to try our rooftop, which was been a little too crowded to feel safe lately.
I decided to see whether the APM 140 was portable enough to haul upstairs. To my astonishment, the telescope slipped easily into the Gitzo carrying bag that I've been using for my Vixen refractor. That sliding dew shield goes a long way. It also barely felt heavier, and it suddenly dawned on me that, because the APM can sit well on the same mount and tripod, it's actually just as portable as the Vixen. Imagine that: a nearly six-inch-wide, portable refractor! To my relief, the rooftop was relatively empty. I unpacked and set up the telescope in under five minutes, and of course the APM acclimates so fast that it was immediately ready to go. Jupiter was up first. To my delight, I'd tuned in on time for another shadow transit - my third in three weeks! To think I'd never seen one before. This time it was plainly obvious that it was Io's shadow on the Jovian clouds; I could clearly make out the moon as a tiny orange disk. How the mind soars to imagine its volcanoes belching sulfur into the radioactive torus swirling around Jupiter. I switched to Saturn, but the planet was just a bit lower in the sky than Jupiter, and the difference in seeing was plainly noticeable. Turning back to Jupiter, I was struck by how much better - I'm afraid there's no other word for it - the planet looks through the APM than it does through the Takahashi FC-100DC, even when the smaller telescope has its focal extender screwed in. The biggest difference, I find, is in the color. Jupiter's reds typically look a pale pink through the Takahashi, but they are clearly red - in the case of the Great Red Spot, a vivid crimson - through the APM. I also noticed that my Delos eyepieces offered a notably better view then the Naglers, for what it's worth. Both made by the same company, of course, but the Delos seemed to have just a bit more contrast, and they were definitely easier on the eye to use. I'm thinking now that I should swap my 9mm Nagler for a 10mm Delos, if I can do it while breaking close to even. As I admired Jupiter with the 6mm Delos screwed in, for a magnification of 163x, the seeing suddenly stabilized for around 20 seconds, and the planet suddenly snapped into crystal-clear focus. I was taken aback; I almost couldn't believe what I could make out. It was a textbook view of the planet - in that it could have literally appeared as a Hubble photograph in a textbook, held at arm's length, while squinting ever so slightly. The Great Red Spot and the swirling, complicated clouds surrounding it beautifully framed Io's shadow, and the details in the cloud belts were so richly textured . . . I was just astonished. When the seeing returned to normal, I could do nothing but pack up and leave. There are times in amateur, observational astronomy when you've had your fill and you need to step away to process it for a while. I packed up - again, in under five minutes - and stepped quietly downstairs, knowing I was sated for the week. A note on the APM. Earlier this year, I would not have believed such a telescope was possible - or at least, I would not have believed I would ever own one. Here is a refractor that, at 5.5 inches in aperture, excels at just about every object, but somehow manages to be grab-and-go portable. It weighs just a few pounds more than my much smaller Vixen - which is itself light for its aperture - and so a relatively light mount and tripod can comfortably handle it. I can carry it with ease. Its focal length is fast enough for wide-field views, but slow enough for magnificent planetary observation. It offers absolutely sharp, color-free views and first-class mechanical quality, at least on par with my Takahashi, but somehow costs just a hair more than that much smaller refractor - and about the same as the Vixen. Somehow, it cools down just about as fast as they do. It's true that my APM has what I gather is an unusually high strehl ratio - in other words, its optical quality is better than average - so my experience with this model might be unusually good. Even so, tonight's look at Jupiter - not exactly the easiest object to view - made me wonder why anyone would need or want anything more expensive at this aperture. My cup was full, and I can't imagine that any other portable telescope would have filled it further. After two weeks of rainy, stormy weather, the skies cleared over the last two nights, and seeing conditions were, remarkably, better than average. On the evening of the eighth, I marched out of our apartment with my Takahashi, focal extender installed, to have a good look at Saturn and Jupiter. Both are now fairly high in the evening sky, beginning at around 9:00. After a fifteen-minute walk to my favorite park, I was ready to go. Jupiter, it turned out, was a little disappointing. I did manage to catch some tantalizing glimpses of complex details in the planet's belts, including one enormous ruddy patch in the north equatorial belt. But, on the whole, the colors and contrast were a little muted from what they can be. Atmospheric transparency was a little lower than average, I thought, so maybe that was to blame. Or maybe the APM 140 has spoiled me. When I switched over to Saturn, however, I was rewarded with one of my best-ever views of the planet. The Cassini Division stood out sharply along the entire ring system, and the thin black shadows visible behind the rings and on the rings, behind the western limb of the planet, were perfectly crisp. I thought I could make out no fewer than two grayish cloud belts - normally, I can clearly see just one. I admired the beautiful planet for a good long time before packing up and heading home. Then, on the morning of the 10th, I set out at 3:30 AM to observe the Moon and Mars. It's amazing what we do to ourselves, as amateur astronomers, to pursue our passion. I can never sleep well when I know I'll have to observe in the early morning, and on this night I'd had maybe a couple hours of sleep. Would it be worth it? As I left my building and set out for the park with the Takahashi, I noticed two things. First: the Moon and Mars were really high in the sky! Second: there was space in my building's illuminated "back yard" (as my daughter calls it) to set up the telescope. Why wouldn't I just do that and save myself the walk? I was awfully tired, after all. I went for it, and I can't recall making a more disastrous observing decision. After seeing up in one corner of the area, the sprinklers, which had been silent, suddenly started up exactly where I was sitting. In a panic, I grabbed what I could and rushed to another part of the yard. Nothing was damaged, but my eyepiece - a TeleVue Delos - did fog up completely. Ugh. Now I was forced to set up directly under no fewer than four bright lanterns. Maybe it wouldn't matter, I tried to convince myself. Oh, it would. Stray light kept entering the eyepiece, spoiling the view with ghostly reflections. Both Mars and the Moon also had a halo that's not usually there - partly because of the mist rising from the sprinklers, I decided. I also decided that stray light washed out some of the contrast on Mars. And what a pity, because a look at the Moon quickly convinced me that seeing was as good as it has been all year. I'm certain I made out at least a couple craterlets in the crater Plato - a sure sign of excellent seeing (and an excellent telescope). Mars was disappointing, only because it was so obvious to me that I would have seen far more had I just walked to that park. Still, dark albedo markings repeatedly shimmered into view, and the southern polar cap was obvious - if a good deal smaller than it had been earlier in the year (or have the bright clouds that make up the southern polar hood dissipated?).
Then the sprinklers turned on near me - it turns out I hadn't escaped them entirely. Why not soak pavement during the entire night? It's not like we're in an ecological crisis or anything. Once again I packed up, this time for good. All in all I was happy to have had a good look at the Moon, and grateful for the lesson - don't use the backyard! - well in advance of Mars's opposition this year. Still, after sacrificing so much sleep I had hoped for a better view of Mars. Next time! |
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