Why marathon?
After more than 30 years of Messier marathons, there’s one approach I’ve never tried: doing it alone. To guarantee you’ll enjoy the marathon, make it a social event. Every astronomy club with a dedicated cadre of observers schedules a Messier marathon. Hard-core amateurs hold it as close to New Moon as possible, whenever that falls in early spring. Most clubs, however, schedule their marathon for the Friday or Saturday night (or both) nearest New Moon.
In 2020, New Moon in March falls on Tuesday the 24th. Ideally, we’d go out that night and see all 109 objects. Many of us, however, must work the next day, so our best options become either the preceding Saturday, March 21, or the following Friday, March 27. Only because March 21 comes first, I suggest you aim for that date, and keep the 27th (or 28th) as your “bad weather” backup date.
Above all, a Messier marathon is meant to be fun — a time when observers come together with a common purpose. And, as an added bonus, being with a group might get you thinking about a new equipment purchase.
If you don’t see all the Messier objects this year, whether it’s due to your schedule or clouds, 2021 has no New Moon within the marathon window. You’ll instead have to wait for 2022, when New Moon falls on April 1 (no fooling). So, I wish you all clear skies this month.