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Wild Card 007: "When the Atmosphere Gets Out of the Way!"

Posted by Rick Shaffer   09/02/2004 12:00AM

More years ago than I’d like to think about, I joined the Junior Texas Astronomical Society in Dallas. The next year I became president. One of the privileges of being a member was that members of the “senior” club would come out to the club’s observatory in DeSoto, Texas, south of town, and allow us to use the 12.5” f/8 Newtonian they had mounted there.

I don’t remember much of the details of the telescope, except that it wasn’t thought to be a particularly good one. Although it had a very heavy metal framework tube, its mount only featured 1” shaft, so the telescope vibrated a lot when focusing it. I also wasn’t too fond of the drive system. There were no clutches. The telescope had to be cranked around the sky! There was a lot of steel, a lot of concrete block, and, if I remember correctly, the dome was all steel. Very little thought was given to avoiding heating up the building in the Summer.

As you might imagine, the views through this telescope were less than inspiring. I didn’t have a clue about it then, but I realize now that the reason very few “wow!’s emanated from the observatory was because there wasn’t a lot of heat emanating from it. It had stored it up all day, and it took all night to release it, and only reached thermal equilibrium about sunrise, just in time to take on a fresh supply.

But one night, the atmosphere “got out of the way”. We had opened up the building when we had arrived, but everybody was using the portable telescopes we’d brought, and no one had spent much time using the big scope in “the mausoleum”, as I sometimes called it. Just before closing up and going back into town, someone suggested that we take a last look a Jupiter, which was about an hour past the meridian. That guy went inside and pointed the telescope while we continued packing up our gear.

We went inside, and I asked him what power he was using. He replied that he was using the highest power eyepiece with which the telescope was equipped, a 4-mm ortho, which yielded about 635X. I, of course, asserted that he’d chosen much too high a power. But I was wrong, big-time wrong!

What we saw was stunning! In fact, it was so stunning that we almost couldn’t get the first person to have a look to let anyone else look! What I saw when my turn came up was a revelation. The equatorial belts were a riot of turbulence, all of it on Jupiter! The Great Red Spot was nearly at the Jovian meridian, and it was in the process of “eating up” a smaller white spot. There were several of the brownish “barges” the seem to move along the belts, and several delicate bluish-tinged festoons reached out of the North Equatorial Belt into the Equatorial Zone.

Beside the wonderful view of Jupiter, it was apparent that there was no evidence of atmospheric turbulence at all, even with a half dozen people in the dome. We took turns “drinking in” the exquisite view for about an hour, but then just had to leave because several of us had jobs delivering the Sunday morning edition of the Dallas “Times-Herald” the following morning. (One particularly-galling thing I remember is that it never occurred to me to even look to see if the telescope was resolving the disks of the Galilean moons. It must have been, but I just didn’t have the sense to look!)

This is only one of several occasions when I’ve been lucky enough to observe the sky with a telescope when the atmosphere “got out of the way”. Here are a few others:

--I lived in Altadena, CA, from 1978 until late 1994 while working at the Jet Propulsion Laboratory in Pasadena. I went to Mount Wilson on several occasions, and got some incredible views under essentially perfect seeing at some star parties hosted by the LA Astronomical Society. I also got an incredible view of both Saturn and Jupiter from a turnout next to the transmitter for Channel 9 in the late Spring of 1982. We were using my telescope with a 17.5” “visiting” mirror in it while my 19” mirror was being refigured. I had it stopped down to 12.5” because the mirror was one of those that had been figured with the wrong lens in the tester at Coulter. (To their credit, they fixed it later for its owner.) We were using a 4-mm ortho to get 500X.

My friends Steve Whistler and Dave Morris were with me. Dave was a “newbie” to Astronomy, but he was very inquisitive and thorough in whatever he did. When his turn came to view Saturn, Dave turned to me, and in a matter-of-fact tone of voice, asked me, “So, is that little red disk next to Saturn Titan?” (He’d remember to look around, something I still hadn’t quite mastered. I always went for the “big gaudy ball in the middle”!)

--About the same time, I went over to Pomona, CA, to look through Jeff Schroeder’s magnificent 11-inch refractor. (This was the first telescope Jeff ever built, and he did the whole thing himself, including the lens!) Jeff had just finished yet another “minor refigure” of the #3 (concave) surface to remove a last little bit of spherical aberration, and the lens was essentially as good as he could make it. But what made the night so special was the Second Stage Smog Alert we had that day. That meant that the air was so stagnant that the smog had just built up to unhealthful levels.

What the smog meant for us was that Jupiter and Saturn, if we could find them, would be a bit dim, but rock steady. Jeff found Saturn in his binoculars, and then with the 11’. It was magnificent, with a few delicate festoons in the belts, and just a hint of “roughness” in the rings. Soon, however, it had faded in the smog in the West over downtown LA.

Jupiter was next. If anything, it was better than Saturn. How it looked to us was a reprise of that first great view through the 12.5” in Texas. We looked and looked and looked until the smog captured Jupiter as well.

--In 1986, another staff member at JPL had formed a partnership with a travel agent to do some special guided tours to view the apparition of Halley’s Comet. He hired me to provide telescopes for his events, and several fellow members of the Polaris Observatory Association and I staffed these events. One of them was a “Halley’s Comet Weekend” in January at Victorville, CA. We used a viewing site about 30-miles away at Shadow Mountain, East of Edwards AFB. We had a warm, dry night for our “customers”, and showed them things we remarked to each other that many life-long amateurs had never seen, and might not ever see. (Color in M-82? Just a hint of pink.) Upon driving “down below” to Pasadena the following morning, I found that the entire basin was enshrouded in clouds.

The “piece de resistance” was the Pleiades, which I only viewed after I’d gotten the 20” rolled up the ramp into my van. I had just acquired a Celestron “Comet Catcher”, and had an excellent 26-mm TV Plossl eyepiece in it for 19X. What I saw was the complete view of the Pleiades as if in a long-exposure photograph. The nebula in which the Pleiades are embedded had the bluish striations just like in the pics. I stared and stared, until the weather changed. A “dry cold front” blew through about 12:45, and the seeing went back to being merely ordinary. The “Night of My Life” was over….

--In the mid-80s, we had two nights of great seeing coupled with great transparency at the observing site of the Polaris Observatory Association in the Lockwood Valley in Ventura County, CA. On one night, several of us clearly saw M-33 with the naked eye when it was only about 45-degrees above the horizon. Of course, the Andromeda Galaxy was as good as I've ever seen it.

On another night, my friend Steve Edberg pointed out the Zodiacal Band to me. This is a very faint band of light that follows the Ecliptic, hence the name. It is believed to be caused by sunlight being backscattered by small dust particles in the plane of the Ecliptic. I’ve only seen it one other time, from a campsite about an hour North of Flagstaff on the way to the Grand Canyon.


I’ve been extraordinarily lucky. I had the good fortune to live in a place from which I could travel to observing locations that feature great seeing, and occasionally, great seeing coupled with great transparency. From conversations with other amateurs, I’ve come to the conclusion that many amateurs can go their entire careers and not experience the kinds of nights I’ve recounted above.

In the next two installments of this unusual three-part version of “Wild Card”, I’ll whet your appetite for great seeing by recounting some notable observations made by truly great observers under equally great conditions. This will include tales of pre-spacecraft-visit observations of features on Mars and Saturn that were allegedly discovered by spacecraft imaging. That’s next week.

In the week after that, I’ll go over ways you can grab some great seeing for yourself.

RICK SHAFFER is an astronomer, writer, teacher, and designer/builder of telescopes and museum exhibits. He lives in Sedona, AZ, where the views of the Red Rocks are often a LOT better than the astronomical seeing!