Messier Marathon: How to See All 110 Objects in One Night

There is one night each year when the sky offers you an extraordinary challenge: observe every single one of the 110 objects in Charles Messier's famous catalog between sunset and sunrise. It is called the Messier Marathon, and if you have ever wanted to push your observing skills to their absolute limit, this is the event that will do it.

The concept is beautifully simple. The Messier catalog contains 110 of the brightest deep-sky objects visible from the Northern Hemisphere, galaxies, nebulae, star clusters, and one supernova remnant. Most of the year, the Sun sits in front of some portion of the sky that hides a few Messier objects. But during a narrow window in mid-to-late March, the Sun occupies a gap in the catalog, and all 110 objects become theoretically accessible in a single night.

When to Attempt a Messier Marathon

Your window is typically mid-March through early April. The ideal night has two requirements:

• New Moon or thin crescent. You need the darkest skies possible. Many of these objects are faint, and moonlight will wash out the trickiest ones.
• Clear skies from dusk to dawn. You need every minute. A cloud bank at sunset or before sunrise will cost you several objects at the critical endpoints of the marathon.

Equipment You Will Need

You do not need exotic equipment, but you do need the right setup:

• Telescope: A 6-inch to 10-inch Dobsonian is ideal, fast to move, wide field of view, and enough aperture to catch faint objects quickly. GoTo mounts work too, but some marathoners prefer the satisfaction of star hopping to each target.
• Eyepieces: A wide-field eyepiece in the 25-32mm range for finding objects, plus a medium power eyepiece (12-15mm) for confirming identifications. See our eyepiece guide for more detail.
• Finder charts: Printed charts for each Messier object, organized in observing order. Several free marathon-order charts are available online.
• Red flashlight: You will be reading charts all night. White light destroys your dark adaptation.
• A checklist: Number 1 through 110, in marathon order. There is nothing more frustrating than realizing at dawn that you skipped M79.

The Critical Windows: Sunset and Sunrise

The hardest objects are at the very beginning and very end of the night. These are the objects closest to the Sun's position in the sky, and they hang briefly above the horizon in twilight before disappearing.

The Sunset Sprint (first 30 minutes)

As soon as the sky darkens enough to see stars, you need to sweep up the objects setting in the west. This typically includes:

• M74 in Pisces, a face-on spiral galaxy with low surface brightness. This is widely considered the single hardest object in the marathon. Miss it in the first 20 minutes and it is gone.
• M77 in Cetus, another galaxy low in the west.
• M33 in Triangulum, large and diffuse, it needs dark sky and a wide field.
• The Andromeda group: M31, M32, M110, these are bright but setting fast.

The Sunrise Sprint (last 30 minutes)

At the other end of the night, you are racing dawn to catch objects rising in the east before twilight washes them out:

• M30 in Capricornus, often the very last object, barely clearing the eastern horizon before dawn brightens the sky.
• M72 and M73 in Aquarius, small and faint, needing a clear eastern horizon.
• M2 in Aquarius, a bright globular, easier than the others but still needs to be above the horizon.

The Middle Hours: Steady Progress

Once you survive the sunset sprint, the pressure eases. From roughly 9 PM to 4 AM, you have the bulk of the catalog available in the sky. Move methodically through the constellations:

Tips from Marathon Veterans

• Eat and hydrate. You are up for 10-12 hours in cold air. Bring warm food in a thermos, plenty of water, and high-energy snacks. Hunger and dehydration destroy concentration.
• Dress warmer than you think. Even in March, standing still for hours gets brutally cold. Layer aggressively. Bring chemical hand warmers for your pockets.
• Take brief breaks. A five-minute stretch every two hours keeps you sharp. Rushing while exhausted leads to misidentifications.
• Accept imperfection. Very few observers bag all 110 on their first attempt. Getting 90 or 100 is a remarkable achievement. Come back next year for the rest.
• Observe with friends. A marathon is more fun (and more motivating) when you share it. Take turns confirming objects and keeping each other awake in the small hours.

What Counts as a Valid Observation?

This is informal, there are no official rules. Most marathoners count an object once they have positively identified it in the eyepiece and confirmed its position against the chart. Some log a brief description; others simply check it off. The point is not to study each object in depth but to prove you can find it. Detailed observations are for every other night of the year.

If you are new to deep-sky observing, start with our top 10 Messier objects for beginners before attempting the full marathon. And if you want to sharpen your finding skills, our star hopping guide is essential preparation.