by Albert Highe
The warm weather and clear skies drew a rather large crowd to Montebello Saturday night. I estimate that at least 30 scopes were present. The temperature dropped to the mid-40's with a relative humidity between 38-51% - very dry. Fears of high winds were unfounded. Except for the Sun's soft sigh at nightfall, the wind was dead calm.
To pursue faint fuzzies, I prefer darker skies than those at Montebello. So, I generally observe brighter objects there. I have never done a Messier Marathon, and all the discussion on TAC made me wonder about what it would be like. So, despite the local light pollution, I planned to conduct a brief Messier Marathon until moonrise around 10:30PM. I brought my 12.5" f/5 ultralight and mostly used a 14mm Radian.
The March 2002 issue of Astronomy has a recommended order for observing the Messier objects in a single night. I show only the first 60 objects listed.
The Astronomy article recommends observing some of the brighter objects during twilight (M45 - M35). Although I did as they suggested, I also returned to these objects later to observe them when it was darker. Contrary to what the article implied, I didn't feel a rush to clear some of the easier objects off my list. In fact, I found myself waiting for it to get dark enough so that I could observe the "evening rush hour" objects (M31 - M74). I had time to observe all of these objects and then go back and do them all again when it was a little darker. With the 12.5", only M74 was a challenge early on.
After the initial "rush", which wasn't, I methodically worked my way through the list in the recommended order. Although I know the locations of my favorite Messier objects from memory, there are many I haven't seen in years. To locate and confirm individual objects, I used my favorite pocket atlas "The Observers Sky Atlas" by E. Karkoschka. It has wonderful little finder charts indicating the locations of all the Messier (plus many other) objects. There is also a handy reference list to direct you to the proper page.
For the most part, the recommended order for observing the Messier objects makes sense. However, there were times when I felt unnecessarily jerked around the sky. For example, as already noted, I would recommend observing objects M45 - M35 after the evening rush hour. M45 should come after M34 and M35 should come after the Auriga clusters M36 - M38. M42 and M43 should come after M1. M41 should come before M50.
One of the more difficult objects was M101. It happened to be immersed in rather strong sky glow at Montebello. The objects in the "Realm of the Galaxies" were also rather difficult because of light pollution. They would have been very difficult with smaller aperture in these skies. On the other hand, there were few other galaxies visible to distract me.
I also found the Astronomy article overly pessimistic. It mentions hitting M81 and M82 just before midnight, and entering the "Realm of the Galaxies" (Coma and Virgo galaxies) around 1AM. I had observed all of these objects, completing all of the 60 objects listed above, just after 10PM. I stopped because the rest of the objects just hadn't risen above the horizon or light pollution yet. If I were actually trying to complete the Marathon, I'd go to bed now and sleep for at least four hours.
I have the following conclusions. The Messier Marathon is a rather easy stroll if you have familiarity with the sky, have a scope with reasonable aperture, and use a good finder and charts that you know well. The skies don 't even need to be particularly dark although that would help with smaller apertures. I think the most difficult part of the Marathon is staying awake all night. Consequently, I'll reserve my dark sky sessions for other pursuits and complete the remaining 50 objects in another mini-Marathon in a few months.