You know we backyard astronomers can have wonderful star parties, but did you know that we also do… marathons?

The Messier marathon is a favourite (and very hard) challenge amongst new and veteran astronomers.

It involves finding all 110 deep space objects (galaxies, nebulae, star clusters) on the Messier calendar. This is hard enough anyway, but the twist with a Messier marathon is it’s completed in only one night.

Just planning for a Messier marathon is a challenge. Our guide will share everything you need to plan and execute your own backyard Messier Marathon or enter one organised by your astro club.

So, let’s dive in…

Messier Marathon Basics

Okay, let’s begin with a brief background check.

Charles Messier lived and worked in France, which is in the northern hemisphere. So people living in the southern hemisphere are out of luck. There are a few Messiers visible south of the equator, but no marathon to be had… sorry.

Even in the northern hemisphere, things are not so straightforward. Latitude determines a lot about what you’ll see – or miss out.

The northernmost Messier object (Messier 82 – the Exploding Cigar Galaxy) is at almost 70° declination. This means you have to be north of 20 degrees south latitude.

The southernmost (M7, the Ptolemy Cluster) is at -35° declination, so you have to be south of 55 degrees north latitude.

Although the language is a little confusing, the upshot is we can only see every Messier at latitudes between 20° south and 55° north.

Because that includes objects on the horizon (where they are essentially unobservable) 25° north is the best latitude for a Messier marathon. Here, at the right time of year, all the Messiers gain enough height over the horizon for good observation.

That makes areas from Key Largo, Florida an amazing marathon location. But, in reality, you can stretch to 35° north and still see all 110 objects in a night. This opens up most of the southern continental US for successful marathon viewing.

When is Best for a Messier Marathon?

The ‘right time of year’ is a short few weeks from mid-March to early April (either side of the spring equinox). Within that period, dark nights around the time of the new moon are best for a Messier marathon.

Even then, you’ll need a good dark sky site. Many of the Messiers are faint and need favorable seeing conditions.

Remember, you’ll have around 11 hours of darkness. To find all 110 objects means you only get 6 minutes to locate and observe each one. The darker your site, the easier this will be.

Discover which galaxies are easiest to see

Resources for Messier Marathon Planning

The number of objects you’ll see is heavily dependent on your location and time, which also determines the order in which you’ll see those objects.

Online Messier Marathon Planner

Which is why you need this Larry McNish’s Messier Marathon Planner. It is the online resource for Messier marathon planning.

Initially, it may seem complicated, but with a little patience, you’ll get what you need. First off, enter your location, marathon date and press ‘submit’, as per the diagram below.

Messier marathon software

How to fill in Larry McNish’s Messier Marathon Planner

Secondly – you’ll now see a spreadsheet of the best order to see all the Messier objects. The list will say which ones can’t be seen from your location or on your date.

Messier marathon spreadsheet

Messier marathon spreadsheet

For a full key to all the terms used in the spreadsheet, click here.

Other Useful Messier Marathon Resources

Use the free software, Stellarium, in conjunction conjugation with the McNish planner, so you’ll know in advance when and where you will come across an object.

Marathon success is all about your speed of object locating. In the field, we recommend SkySafari 5 Pro on the iPad as a quick and easy way to locate your next object.

Many of us find that there’s more enjoyment in a better understanding of what we can see. If that’s true for you here’s the Wikipedia list of all the 110 Messier Objects. It includes a table with a picture and more info. Each one also links to its own page for extra detail.

Getting Ready for Your Messier Hunt

Thankfully, this is the simple part. There are a few preparations to make, and this section quickly flies you through them.

Be sure to choose a dark and quiet location, away from the city lights. Preferably, use an elevated location, to widen your field of view by rising above tall trees and buildings.

Get there early, set up in the light and relax until dark. You’ll be looking for your first objects soon after the sun sets, so don’t lose precious hunting time fumbling with your scope in the dark.

This marathon will take an entire night, from dusk to dawn, so you’ll need some basic supplies for comfort.

If you have it, a good observing chair will go a long way in making the stargazing comfortable. Get a water bottle or Thermos, a night viewing torch, your iPad with SkySafari 5 pro installed or Pocket Sky Atlas and you are all set to explore! Oh, and don’t forget food – you will need to eat as you search.

If you plan to take pictures of the objects through the telescope as you see them, use a timestamp to prove you did the marathon in a single night!

And here’s a sky-map from Wikipedia, showing the positions of messier objects and other fine details. If you wish, you can take a printed copy of it and have it by your side whilst you try to spot the objects in the sky.

Messier Star Chart

Messier Star Chart (Wikipedia)

As you can see, it even has the constellations, so navigation isn’t a problem when you’re under high-speed observing pressure.

Tips & Tricks to Improve Your Messier Hunt

1) Star-Hopping and angle measuring are techniques used to find small and less luminous objects in the night sky. They will come to your rescue when you get going with your marathon. You’ll find that a decent pair of binoculars will help you move around the sky quickly.

2) Don’t expect too much. Astronomical objects always look better in photographs. A small telescope won’t show much beyond a bunch of grey fuzzy patches. But, once you spot an object, you can immediately look up its actual picture on to see how it really looks.

3) But… you can also look out for some details, like M40’s double star, and the M73 asterism – a pattern of unrelated stars. See if you can spot such differences; it adds to the adventure!

4) Your next best chance of completing the Messier marathon is the weekend of 20th/21st March 2021, when the moon will be heading towards new. If you can have a day off work, the perfect night (clouds permitting) is Tuesday, March 24th. Get it in your diary now!

Wrapping Up

You are ready to tackle this challenge now, but you should know it is really, really hard to achieve a perfect score.

Don’t be too hard on yourself if you miss one or two (or even eight or nine) of the 100+ objects. Be assured that even the experts struggle to achieve it.

If you tried early enough in the season, you could get a second bite at the cherry later in the March / April window. Otherwise, it’s onwards to next year and planning for a better result.

Messier Marathon Further Reading

Messier Marathon Field Guide

(Click for Amazon price)

Links: Please note, some of the links in this article are affiliate links. You can find out more by clicking on ‘affiliate links’ in the footer.

Product images sourced from