Messier Marathon 2027: dates, best nights and how to do it
A Messier Marathon is an attempt to see all 110 objects in Charles Messier's catalog in a single night, from dusk to dawn. It only works around the New Moon in mid-March to early April, when the Sun sits in a stretch of sky with almost no Messier objects, so nearly the whole catalog is above the horizon at some point during the night.
2027 Messier Marathon dates
| Night | Moon | Rating |
|---|---|---|
| Sat March 6 – Sun March 7, 2027 | Thin waning crescent, rises just before dawn | ⭐ Best weekend |
| Sun March 7 – Mon March 8 | New Moon March 8, 1:29 AM PST | Best weeknight |
| Sat March 13 – Sun March 14 | Waxing crescent in the west after sunset | Backup; evening objects harder |
| Sat April 3 – Sun April 4 | New Moon April 6 | Backup; M74 and M77 likely lost in twilight |
New Moon times computed with the PyEphem library. US Daylight Saving Time starts March 14, 2027, so times are standard time for the main weekend.
The observing order
- Dusk, low in the west: M77 and M74 go first and set fast, then M31, M32, M110 and M33.
- Early evening: the winter sky: M52, M103, M76, M34, M45 (Pleiades), M79, M42/M43, M78, M1, then the clusters M35–M38, M41, M93, M47, M46, M50, M48 and M44, M67.
- Late evening: Leo and Ursa Major: M95, M96, M105, M65, M66, M81, M82, M97, M108, M109, M40, M106, M94, M63, M51, M101, M102, M53, M64, M3.
- Around midnight: the Virgo Cluster, the hardest stretch: M98, M99, M100, M85, M84, M86, M87, M88, M91, M89, M90, M58, M59, M60, M49, M61, M104.
- Small hours: M68, M83, M5, M13, M92, M57, M56, M29, M39, M27, M71, then Ophiuchus and Scorpius globulars M80, M4, M107, M12, M10, M14, M9, M19, M62.
- Before dawn: Sagittarius and Scutum: M6, M7, M8, M20, M21, M23, M24, M25, M18, M17, M16, M28, M22, M69, M70, M54, M55, M11, M26, then M75, M15, M2, M72, M73 and last of all, M30 in morning twilight.
Tips for a successful marathon
- Pick a site with a low, clear western and southeastern horizon. Dark sites in the Anza-Borrego desert are popular with Southern California observers.
- Align your GoTo mount before dark, or practice star-hopping the Virgo Cluster a month earlier.
- Use red light only; MessierGenius has a red night mode.
- Bring layers, hot drinks and a checklist. The free MessierGenius Marathon checklist lists all 110 in observing order and logs each one you find.