lunasat.jpg (7k)
Starry Night simulation

Occultation of Saturn

1997 Dec 8

Despite feeling tired, I decided to set my scope up in the driveway to watch the occultation of Saturn. I also attached the camera to the scope. Luckily my EOS Elan has a clear screen, so it was very easy to watch the event through the viewfinder. I wasn't timing exactly, but it was over by 11:18:03 by my watch. It sure didn't take very long! Very cool to see the planet slowly slide out of view. *IF* the pictures come out halfway decent, I'll post them on a web page. I have to admit to being lazy about the pictures and just bracketed between 1 and 2 second exposures with ISO 200 film. I hope others of you were able to see this event. Does anyone know when this will happen again?

-- Richard Navarette

At 11:00 pm the weather was very iffy in Carmel Valley. It had drizzled a little earlier and there were large grey clouds coming. I set up the Intes half out of a sliding door to a second story deck/balcony. The eaves would protect the scope if it rained again.

Holes in the clouds allowed me to see Saturn disappear. The turbulence from the open doorway made the seeing pretty poor. So, I watched it at 51X.

By midnight it had cleared and I moved the scope out on the balcony and increased the power to 120X. Saturn emerged just off of the northern edge of Mare Crisium as Starry Night predicted. I wasn't sure the lunar surface image was that well aligned.

Duration of the occultation was 59 min. 22 sec. according to my stopwatch. I didn't get accurate start or stop times.

The emergence was quite spectacular. It is interesting to see these two objects in the same field. The difference in scale is a little surprising.

I was glad that the weather cooperated. The hills on the south side of the valley were shrouded in mists. From my point of view they looked beautiful in the moonlight, but I wouldn't wanted to have been over there trying to observe. :-)

-- Robin Casady

I saw it, too! From Fremont Peak. When I arrived just at sunset, it was foggy :-( But I decided to wait it out for a while and after an hour or so it cleared enough for me to set up my Meade LX200. There were patchy clouds blowing by all night but only very briefly enough to actually obscure the Moon. It is amazing how well you can see it thru clouds. I never had any doubt after the fog cleared that I would see the occultation.

(BTW, it was incredibly wet. My scope was literally dripping; had to run my dew heater at 1/2 power all night. And windy and cold! By the time I left, there was frost on my car's roof! I even found a few patches of snow along the road. I hate winter :-( And the seeing was very bad. At times it was into the arc*minute* range, you could see the lunar craters swapping places with each other! Fortunately, that didn't matter much for this event.)

I had a lot of time on my hands. I was set up and ready to go by a little after 6pm and the occultation wasn't until 11:15. But I had cleverly brought my Rukl's Atlas of the Moon :-) So I alternated between crater hopping and sitting in my car warming up. I'm a complete beginner as far as lunar geography (selenography?) goes so I concentrated on the big easy stuff like Copernicus, Clavius and of course, Ptolemaeus. I saw a nice double sunrise ray in Palus Epidemiarum (you know the Marsh of Epidemics, love some of those names :-) It seems that sunrise/sunset rays are quite common. I think I've seen one about half the times I've looked at the Moon. Then I decided to track down the Apollo 11 landing site. Strange to gaze at that distant and alien landscape and think that men actually walked there. And so sad to think that it was more than 25 years ago with nothing since :-(

Of course, a big cloud covered the Moon just as the occultation was beginning. But all it did was dim the colors a little. After waiting all night it went by awfully fast! I missed seeing the leading Saturnian moons disappear (the cloud got them) but I did see the Moon cover Titan.

Then hang around for another hour for the reappearance. This time I tracked down a few easy things on the other limb where Saturn was to appear -- Mare Humboltianum, Endymium, Lacus Spei (Lake of Hope!). The binoviewer is really wonderful on the Moon. For the planets, its nice but kind of dim. But for the Moon it is like flying. Amazing.

Not having any choice about it, I had saved the best for last: the reappearance. Very cool to see the rings climb up above the limb. They appeared to be exactly vertical, It looked like a ghostly arch. (Starry Night's rendition of this event is remarkably accurate; see the image at the top of this page.)

Then Saturn's disk appeared making it look like a fat rocket blasting off. But "blasting" isn't right, it seemed to be more like antigravity, so slowly and silently lifting off and drifting into space. The illusion of lifting off was much more pronounced this time than when I saw the graze back in September.

As Robin said, it is cool to see them together and marvel at the screwed up scale. The apparently huge Moon is actually only 2/3 the size of Titan which appears as just a tiny dot; our Moon is only 3% of Saturn's diameter. To true scale, their apparent sizes would be reversed (approximately).

Packed up and was home by 2am (driving at only 3/4 impulse :-)

-- Bill Arnett

The saturn/lunar occultation was just amazing!

Around 8pm I went downtown palo alto to do some xmas shopping. As I was heading back to the car around 10:30pm I looked up at the moon and noticed saturn awfully close to it. Better get home.

Once back at the house I dragged the scopes out back onto the patio. The question was.. what power to use.. what scope? It turned out that the 8" f/6 at about 100x gave the best view. About 30 minutes before the event, there was alot of glare in the eyepiece. Fortunately, as saturn got closer to the moon, this glare diminished substantially such that I could see the dark limb of the moon and also saturns moons. About five minutes before the event some lone clouds momentarily occulted the moon!

A quick check with WWV verified that my watch was correct.

At the right time.. it started. I could see saturns moons pass behind the dark limb. (For a moment there I thought just maybe saturn would go in front!) Then the rings got cut off by the limb. Finally, and quickly, the planet and rings (and all of saturn's moons) were behind the moon.

But the real show (imo) was the reappearance!

During the occultation, out came the binoculars for some bright-deep-sky gazing. M31 was visible, but M81/M82 were tough. I also spent a bit of time on the Orion Nebula -- though the seeing was iffy.

By now the moon was getting blocked by some trees to the west. So I gathered the scope, chair, etc, and headed out to the driveway where the view was unobstructed.

Right on time -- and I guessed right where to put the field -- saturn's rings reappeared. This was amazing! Seeing saturn "rising" over the lunar surface was just fantastic. It reminded me of the apollo photos of earth rising over the moon's horizon.

Once it was over I grabbed a camera and took a few shots through the eyepiece of saturn just below the moon. (We'll see how those turn out :^/) Then it occurred to me that this might make a nice wide field shot. Back inside I went to get the ETX for a bunch more photos at prime focus.

Also, I used a moon filter for the rising part. This cut down on glare and also seemed to improve contrast on saturn just a bit.

-- Jeff Crilly

It was amazing and graceful, like the gradual disappearance of a swan behind a shrub on the riverbank, very different from watching a star being occulted like the wink of an eye. Through the ShortTube 80 at 90x, the moon was so bright that the darkened eastern limb looked like the void itself, and when Saturn began to be covered by the glide of the moon, it looked as though it was slipping through a slot in spacetime itself...

...but enough of that stuff :-) The seeing was a bit poor, but the whole thing stood up quite well at 90x. The actual event of Saturn being swallowed by the moon's disc happened rather slowly, perhaps 45 seconds from the first touch to total disappearance. Having to get up at 5:15 AM, I didn't stay for the whole show, although I did linger a bit on the moon, whose terminator was especially lovely and lively with detail.

A beautiful backyard astronomy show...

-- Bruce Jensen

Put me on the "saw it" list. Up at Foothill with Akkana, Paul Mortfield and William Phelps (doing their TV thang; I don't think either actually saw it but Akkana had her 80mm Vixen which showed the event very well).

The occultation was a complete bust; could only see a faint blob disappearing due to heavy local clouding. But the main event, emergence, was perfectly clear and reasonably steady considering the elevation. I was able to make out Cassini's as a marking through the six inch dob (which I thought would be unlikely before the event).

Time predictions and locations by MPJ Astro were right on the money; I misread the moon chart and thought it would come out south of Crisium, but it came out north (in agreement with the program after I later reviewed it.. it has a funky error of "marking" vs. "position").

By counting (didn't want to look at my watch) I got about 30 seconds for the part of the emergence I saw (couldn't time the occultation since we couldn't see it). Anybody have the sense to use a stopwatch? Didn't see the very beginning of the emergence...

-- Dave North

Even before the disappearance, seeing Saturn that close to the moon was unreal. I set up my 80mm Vixen, figuring there was little point in using anything much bigger in the stormy seeing; with a 15mm Panoptic (60x), I could see the whole moon plus Saturn just off the dark limb, and the effect was the same as I sometimes get from observatory visitors seeing Saturn for the first time through a telescope: "That can't be real." Amazing and lovely.

For the disappearance, I switched to higher power, 138x. Paul and William, over at the video console, were muttering about whether they had enough light to continue tracking Saturn through the clouds. I was having no trouble following Saturn through the thin cloud layer -- until a particularly thick clump of clouds passed through and both Saturn and the moon disappeared. Maybe half a minute later, the clouds thinned out enough that we could see the moon again -- along with the last edge of Saturn's rings disappearing behind the dark limb. We'd missed the disappearance by seconds!

Fortunately, the clouds were completely gone by the time of emergence, though all the telescopes were dripping with dew. No one was completely sure exactly where Saturn was supposed to emerge, just that it was somewhere around the south end of Mare Crisium. So we all trained on that area, and David North was the first to spot the rings emerging, considerably north of Crisium. Saturn emerged ring-first. I didn't think to time it; I was too engrossed by the lovely view.

After Saturn had emerged completely, I wandered over to the video setup Paul Mortfield and William Phelps were running. Both the moon and Saturn looked excellent and showed detail; I'll bet the video is going to be great.

We took down the 'scopes and staggered home almost immediately; I hadn't been feeling well and didn't want to stay out any later than necessary, but seeing that lovely re-emergence was worth staying up for.

-- Akkana Peck

Me too, finally...

Last September, I awoke a 2AM to setup my C8 to see that occulation. I had nice views of Saturn...then, slowly, a cloud bank came and covered it and the Moon completely for the rest of the AM! :-(

This time was MUCH better. I setup my C8 on my patio(!) and was perfectly aligned by 10PM. The seeing allowed for the best view of Saturn at 220x. I just let the drive keep Saturn for the whole show. I saw(?) the dark side of the Moon (like a black wall) slowly cover Saturn. I convinced my wife to take a look and she was amazed. As the Moon rolled by, I just waited for the reappearance, and right on time a ghostly Saturn slowly emerged from behind the bright Moon. My wife again saw this, was floored, and will never complain about my astro expenses again!!

This was my first time seeing this and I will never forget it.

-- Robert Dannels

Bill Arnett; last updated: 1997 Dec 9