Parade of Planets and Moons

by Randy Muller

A wild and crazy group of dangerously deranged TAC-SAC observing fanatics took a chance to do some dark sky observing near Fiddletown, California on a completely cloudy 3rd quarter moon evening on Saturday, March 17th, 2001.

The Parade of Clouds

The skies were pretty horrible, but the skies had been horrible during the last month, so we were willing to do anything to maximize our chances of getting any observing in during this dark moon cycle, and this meant going regardless of the clouds on the off chance that things would clear up.

The Parade of Vehicles

I led a caravan consisting of Shneor Sherman (18" truss tube dob; "Shneor" is a Yiddish name and is pronounced "shnair"), Gary Manning (10" dob), Mark Hansen (10" EQ mounted newt), and me (18" truss tube dob). Unfortunately after waiting for about 20 minutes, we left my co-worker Francis Lau behind. He arrived at our meeting site just minutes after we left.

We arrived at the site at 4:40pm, and met Bay Area resident James Webster and his friend whose name I can't remember. James was setting up both 20" and 10" truss tube dobsonians that he built himself. The others I came with set up under the murky skies as if we were going to have clear weather.

After I set up, I helped Mark collimate his 10". It pleased me to hear him later report that he had never had such good views with his scope before.

The Parade of Planets

By this time there was some clearing in the west, and after the sun set, I turned my scope on Venus, which was hanging like a bright jewel in the west. I was astounded at the incredibly large and thin crescent figure showing at 226x power. I had never seen such a thin crescent Venus before!

Shortly after this, as twilight continued to fade, I heard Shneor exclaim about the view of Jupiter he was getting, so I turned my scope on it, surprised at how the sky seemed to be continuing to clear.

The view of Jupiter was astonishing! The seeing was very good, and I could see many, many belts, especially in the northern hemisphere. Within the two main equatorial belts, there was a riot of detail, including a bluish barge, festoons, whorls, spots and general chaos.

Shneor had mentioned that there were two moons very close to the limb. By the time I took a look at about 6:45pm (2:45 Mar 18 UT), I only saw one at first: Callisto (which Gary kept playfully calling "Calista"), which was skimming past the Jupiter's southern limb. I had thought this was Europa at first, because it was significantly darker than the other moons, but I had forgotten how dark Callisto is. Gary was running XEphem (UNIX-based star charting software which I kept playfully calling "exey FEM" and repeatedly asking him if it was an operating system with files and stuff) identified it as Callisto.

I saw the other moon Shneor mentioned beginning to transit Jupiter. It was just over the terminator when I looked, a brilliant yellow-white BB moving across Jove's face right over the South Equatorial Belt (SEB). Because of the color, I guessed it was Io. The color contrast, with Io's yellowish pimple-like appearance laid on top of Jupiter's reddish brown SEB and tan (not white nor yellow) zones was very prominent and thrilling to see.

As Io moved out of the Jovian terminator, I could detect the terminator on the following (celestial east) side of Io, as it contrasted sharply with the light background behind it. Combined with the relatively quick motion, it suddenly took on a marvelous 3D appearance.

Jupiter's an active place! I couldn't wait for the shadow transit which I knew was coming soon.

I next turned my attention to Saturn, which showed a much more placid and organized riot of detail, in contrast to the boiling and stormy chaos of Jupiter.

The charcoal gray C-ring (aka Crepe Ring) was easily visible, as were the A and very bright B rings. The outermost A-ring appeared to have some linear texture in it, although I can't say that I saw the Encke Division.

The terminator was clearly visible against the bright rings in the behind the planet. I could not see the shadow of the planet on the rings.

There was a single thick dark pinkish-brownish belt embedded in the yellowish surface of the planet.

The Parade of Moons

When I looked for moons at about 7:30pm local time (3:30 Mar 18 UT), I could easily see 5 right off the bat: Titan (bright and orange colored) off to the NW, Tethys just W of the rings, Dione SSW of Saturn, Rhea to the SW and Iapetus far to the SW. I had to verify that Iapetus was a moon and not a field star with my star charting software.

With a little study and averted vision, much dimmer Enceladus appeared skimming the south pole of Saturn.

These are the six I have typically seen with my 10", so I decided to try for the other two I've seen with my 18".

After long study and waiting for the seeing to provide good moments of viewing, I finally saw Mimas just E of the rings. It was very, very difficult and only visible intermittently.

Finally, I searched for Hyperion and found it far to the W of the planet. It seemed about as bright as Enceladus.

This was the first time I had seen all eight of these at the same time, and I was quite pleased.

I visited Mark's scope while he too was looking at Saturn, and it looked pretty good. "I've seen belts on Jupiter, but I've never seen that belt on Saturn before!" he exclaimed.

I swung the scope back to Jupiter, and lo, there appeared the shadow of Io. It was a very high contrast black spot with very sharp edges also in the South Equatorial Belt. When the seeing was poor, it faded into looking more like a mottled area in the belt.

The Great Red Spot was also following the shadow.

This transit was great fun to watch!

By now it was dark and then Jim Ster (12" LX-200 SCT, TV-85 refractor and other assorted devices) and his clan arrived, leading Art Freeman and his son Brad (16" sonotube dob and ETX-120).

After showing the shadow transit to the newly arrived visitors, I helped Art collimate his 16". It really pleased me to hear him later saying to Gary that he had never seen 6 stars in the Trapezium (in the center of M42, the Orion nebula) before. When I was first learning to collimate, I, too, was elated when my efforts yielded 6 stars (instead of 4) in my 10" dob.

Sometime after this a spectacular meteor cut a 90 degree swath through the sky. It moved very rapidly, beginning from somewhere in Ursa Major, across Ursa Minor, Camelopardalis and finally into Perseus where it burned out. It was not terribly bright, but it was moving very fast, burning yellow, sparkling a bit and left a bluish smoke trail.

A group of us saw it and we let out intial oohs and ahhs, and then let out secondary oohs and ahhs when it unexpectedly continued after a second or two. By the time three seconds had elapsed, we were talking about how long it was. 3 seconds isn't very long when talking, but it's an eternity for a fast moving meteor!

I happened to notice Comet C/1999 T1 (McNaught-Hartley) as I was looking at my chart, so I decided to take a look at it. It was 4 degrees east of the head of Draco the Dragon.

It was fairly big, and showing a stubby fan-shaped tail. The coma was fairly diffuse, but fairly condensed near the center. The short tail made the whole thing seem asymmetric. It was nice to look at, but nothing like Comet C/1999 S4 (Linear).

At the very end of evening, at about 2am (10:00 Mar 18 UT), Mars had risen high enough to show some detail. I was surprised at how large it already was. There were bright whitish spots on both the north and south sides, with the southern one being much larger. If my previous experience is any guide, then these were Hellas (in the south) and the north polar cap (in the north).

In the center between them was a bright orange-brown area which I am guessing was Arabia. Forming an inverted U around this bright area was a dark region consisting of, I believe, Syrtis Major, Sabaea, Meridiani, Margaritifer, Chryse (where the Mars Pathfinder landed in 1997) and Acidalia. (I am using the wonderful National Geographic map of Mars published in December 2000 to identify these features.)

I also ran the Mars appearance simulator at

http://clamcake.tn.cornell.edu/marsview.cgi

but I had to guess at the features and their relationship to one another, since nothing is labeled on the picture, and even the central meridian value is left off. Just knowing the central meridian for Mars at this time would tell me if I was in the ballpark or not with my identifications. I am guessing the areographic central meridian (ie., the Martian longitude in the exact center of the Martian disk) was somewhere between 30 and 60 degrees. 0 degrees runs through the western (areographic) side of Arabia.

Regardless of the actual identifications, I was pleased to be able to see so much detail this early in the apparition.

Oh, I almost forgot. I actually observed one object on my list of things to observe. I am currently trying to observe all 100 of the Hickson Compact Galaxy Groups, and I logged the following 2 components of Hickson 71 in Bootes:

IC 4381 (Hickson 71a) - 226x, oval, relatively large and diffuse. Difficult. (This is identified as NGC 5008 in Sky Map 7, and as is my wont with all NGC/IC objects, in order to avoid an embarrassing dressing down by Steve Gottlieb, I checked his notes located at the NGC/IC project, and to my surprise, NGC 5008 is missing!)

IC 4382 (Hickson 71b) - 226x, Very small, but with a higher surface brightness than 5008. It has a stellar center.

I made a half-hearted attempt to log Hickson 69 (also in Bootes) earlier, but failed to see any hint of any of its components.

It turned out to be a spectacular night for viewing solar system objects, and especially the parade of planets and moons!

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