Get ready to run this year’s Messier marathon

M42. Credit: Molly Wakeling

When French astronomer Charles Messier looked to the sky in the 1750s, he did not intend to be remembered for his discoveries of galaxies, nebulae and star clusters. Named the “Ferret of Comets” by the French King Louis

While searching the night sky in 1758 to retrieve the predicted return of Halley’s Comet, he encountered a faint patch of light in the Taurus. They determined through subsequent observations that it was stable, and thus not a comet. He recorded its position so that in future it would not be mistaken for a comet. Messier 1 (M1) – later known as the Crab Nebula – thus began his list of “nuisance” objects to avoid when hunting comets.

Connected: Introduction to the General Astronomical Catalog

messier’s list

Messier publishes first version of his catalog for other comet-hunters Journal of the French Academy of Sciences In 1774. It contained 45 objects, of which 17 were discovered by Messier and the remainder were discovered by others. By 1780, the total number reached 80, and eventually 103 when it was published in the Annual. conversation from time to time (knowledge of time) in 1781. He observed all of these primarily with a 100 mm (4-inch) refractor from the Hotel de Cluny (now the Musée National du Moyne) in downtown Paris, where there were certainly dark skies in the 18th century. After 1921, six more objects were added by astronomers who reconstructed Messier’s notes, completing the Messier Catalog at 109 deep-sky objects.

Today, the Messier catalog is a great place for beginning astronomers to learn the art of observation because it contains some of the brightest and most beautiful objects in the sky. Most of these are visible even through modest telescopes, and many can be seen through binoculars.

An important fact about Messier objects is that they are not evenly distributed across the sky. Right ascension is the lack of objects between 21:40 min and 23:20 min; Therefore, from some northern latitudes, it is possible to observe all 109 objects on a single night for a period of a few weeks between mid-March and early April. Although ideally from 25° North, it is possible to catch the entire catalog between approximately 3° and 42° North. For 2026, the best weekend night is March 21, closest to the new moon on March 18.

Messier Marathon was created by several amateur astronomers at approximately the same time in the 1970s, including Tom Hoffelder, Tom Reiland, and Don Machholz. Many astronomy clubs now hold annual events for those willing to stay up all night. Are you ready to take the Challenge?

running a marathon

Some preparation is necessary for the best chance of success. Find a site that has good eastern and western horizons. Arrive early so you’re ready to visit during astronomical twilight. You have to find some targets before it gets completely dark.

make a plan. You’ll need to inspect several targets quickly, so make a checklist to know where to point your scope next. You’ll want a telescope that’s at least 4 inches, but the bigger, the better. And don’t forget important accessories, like dew zappers, tailrods, red lights, chairs, tables and extra batteries.

To catch the first objects before they set, you may need to search in twilight, depending on your latitude. Galaxies M77 and M74 will be particularly difficult. Go through the first 10 quickly, and then you can slow down your pace. But not too much. Use that energy so you have some extra time to deal with the dense Virgo crowd later. I recommend taking a 15 to 30 minute break before visiting these galaxies. Have breakfast, rest your legs and prepare for the next sprint.

After passing through the Virgo cluster, continue down the list at a more leisurely pace until you reach the horizon. Then you can take another break until the Milky Way is higher in the sky. You also have a few hours to take a nap. But do set the alarm!

In the early morning, enjoy 15 objects in Sagittarius, including the Lagoon Nebula (M8) and the Trifid Nebula (M20). A nebula filter is nice, but you’re not doing detailed observations. Check them off your list and continue.

Gather your energy for the last leg: you’ll have to catch the faint globular cluster M72, the dim four-star constellation M73, and the just-emerging globular cluster M30 as the Sun threatens to hide them. You may want to do a dry run on the twilight objects and winding path through the Virgo Cluster before marathon night to have the best chance of success on the actual night.

The most important part of the Messier Marathon is to have fun. Even if you don’t clear all 109 items, you will have improved your observation skills, and you will have a night to remember.

What about M102?

You may have heard about the controversy over M102. In 1781, Messier’s friend and assistant Pierre Méchain discovered it but later believed that M102 was a re-observation of M101, so he withdrew it from the published list. However, there is historical evidence that the Spindle Galaxy (NGC 5866) is what they saw. For what it’s worth, the Hubble Space Telescope’s Messier Catalog images include the Spindle Galaxy as M102.

An imaging marathon?

With the ever-increasing popularity of astroimaging, a photographic Messier marathon is possible. I tried one in 2021, where 100 objects were visible from my San Francisco-area backyard. I managed to capture 66, but it took me a week and two binoculars to do it. Now that I’m more experienced, I plan to try it again this year.

Like the Visual Messier Marathon, some preparation is required. Make sure your mount is well aligned. If your alignment is good enough, you may be able to resolve the plate and center the target, saving significant time.

If you are using sequencing software, create and test the sequence in advance. You may want to rearrange some of the goals so you’re not bouncing back and forth across the meridian depending on where you are on the list.

If you’re using a smart telescope, track how long it takes to find a target and start imaging so you can plan your night. Completing the entire list may require more than one night.

Although some traditionalists may complain that part of the challenge of the Messier Marathon is finding all the objects by hand, imaging so many targets in one or a few nights is a different challenge. The scene and the astrophotography marathon are both difficult and exciting.

On your mark… get ready…

Running the Messier Marathon is not for the faint of heart – it is a challenge to one’s stamina and observation skills. Whether you’re imaging with an automated rig, using the go-to mount, or star-hopping around the sky, the challenge is thrilling.

If the skies clear up around the new moon in March and you’re ready for an epic all-nighter, go out and rock out to Charles Messier’s spectacular catalog!

Target the Messier objects in this order

Planning to run this year’s Messier Marathon? Your ideal sequence will vary with latitude, but this is a good place to start. Make sure to set up before it gets dark and try to log the first few items when there is still some light in the sky.

key: DS = double star; GC = globular cluster; Gal=Galaxy; Neb = Nebula; SC = star cloud; OC = open cluster; PN = planetary nebula; SNR = supernova remnant