by Bob Jardine
This isn't exactly an observing report. More like a summary, scorecard, post-mortem, and some misc. thoughts on marathon observing, especially at Dino.
On Thursday night, 3/14, I set out to do a "dual marathon", a combined Messier Marathon and a Solar System Object Marathon, inspired by a couple of TACos who pointed out that it might be possible to observe all of the planets in a single night. So I put together a list of 20-some objects, including all of the planets, some of their satellites, a couple of comets, a couple of asteroids near opposition, the Zodiacal light, etc.
Here's the scorecard:
| Messier objects | I set out to observe 110 objects (including the "alternate" M102 -- NGC 5866). I got 103 of these, missing 7. That wouldn't be so bad, but I missed 4 really easy ones...more on that later... |
|---|---|
| Solar system objects | I set out to observe 25 objects (originally 27, but I dropped the idea of trying for Triton due to lack of time to prepare, and I dropped Earth's moon due to moving the marathon date up from Saturday to Thursday, only one day after the new moon). I missed 4. The objects I observed were comets Ikeya-Zhang and LINEAR WM1, asteroids Vesta and Juno, planets Venus, Mars, Jupiter and the four Galilean satellites, Saturn and 5 satellites, Neptune, Earth, Sun, and the Zodiacal light. I missed Mercury, Uranus, Pluto, and one of Saturn's satellites. |
I used Harvard Pennington's book, The Year-Round Messier Marathon Field Guide to help prepare. This is a pretty good book, and I think it helped. However, it did mislead me in one detail, by discussing "evening rush hour" and "morning rush hour" as if they were similar problems. The evening rush hour isn't really any kind of problem at all. Only one object is difficult (M74), and that one is really difficult. I spent nearly 1/2 hour on it before succeeding. But the rest of the so-called evening rush hour objects were a piece of cake, including M33 and M110. So there never really was any evening rush at all. On the other hand, the morning rush hour is another matter entirely...
Dinosaur Point, in most respects, is just plain wonderful. The combination of its relatively dark skies and a reasonably large 'scope (in my cases a 10" Newt-Dob) makes the middle part of the Messier Marathon a snap. After M74, all of the rest of the Messier objects were like shooting fish in a barrel...just plain unfair. I had gobs of time, even after a 1.5 hour nap and spending nearly an hour on Juno and Vesta and on sketching the positions of all of Jupiter and Saturn's satellites. I also observed more than 2 dozen additional NGC objects, several of them for the first time.
However, I must say that Dino is no good at all for the morning rush hour. While it has nice low horizons to both East and West, there is a pretty decent (10-15 degrees high) hill blocking a good part of the Southern horizon. This isn't much of a problem usually, but in March, it ruins the chances for two objects: M55 and M75. Normally, these are really easy objects, but at this time of year, they come up pretty late. With a good low Southern horizon, they would still be up in plenty of time to observe well before the start of the morning rush. But they didn't come up over the Dino Point hill until nearly an hour later than normal, thus crowding the morning rush hour even more.
I screwed up on two other easy objects, M2 and M15. Talk about your usual pieces of cake! But on my list (following Pennington), they were after M55 and M75. With a good low Southern horizon, this probably makes sense, but since I couldn't see M55 and M75 until later, I should have reordered and checked off M2 and M15 as soon as possible. But I guess I was too tired to think straight by that time, and I was also preoccupied with Neptune during the last half hour of good darkness. By the time I realized the need to reorder, it was too late.
So the bottom line is that I missed two objects due to a bad horizon (M55 and M75), two objects due to a misjudgment on ordering (M2 and M15), two objects due to just being frazzled and rushed (M72 and M73), and one object that I pretty-much expected to miss: M30. With a good Southern horizon, I'm sure I would have easily seen 4, possibly 6, of those missed 7.
How did the two Marathons interact? Generally, there was no conflict, but when it counted, it was serious. Of course, I observed Venus, Mars, and Comet I-Z before even thinking about any M objects, and both Jupiter and Saturn and all of their satellites were placed nicely so that they could be examined at liesure during mid-evening. Similarly, while I spent quite a bit of time on Vesta and Juno, there was plenty of slack for that in the Messier part of the marathon.
However, I did spend too much time on Neptune, and I think it contributed to my morning problems in the end. I didn't really think this through in advance. I've observed Neptune many times in the past, but always much closer to opposition and always at more optimum altitudes, so I wasn't prepared for how much more difficult it would be with the double-whammy of observing 5 months away from opposition and very low in the sky. Normally, verifying Neptune is no problem, because it is easy to just power it up to become apparent as a disk. But last night I just couldn't do that, so I had to resort to the "which apparent star isn't in the atlas" method, which takes a lot longer. I did manage to verify Neptune, but at a cost.
Finally, my morning rush hour went so badly that I didn't even try for Uranus or Mercury. But even if I hadn't had to include Ms 2, 15, 55, and 75 in the morning rush hour, I think that trying for both M30 and Uranus at about the same time wouldn't have worked well. So in the final analysis, I think there is a serious conflict between the Messier and Solar System Marathons, at least with the present planetary positions.
Bottom line: did I have some fun? You bet! Will I consider doing this again? Ask me again in 11 months ;-)