M5 M7 Messier Marathon From certain latitudes, all 110 Messier objects can be observed in one night during late March or early April (depending on the phase of the Moon). The Messier Marathon, as this is known, is a popular pursuit among amateur astronomers. M13 M16 M17 M20 M21 Systematically organizing information is one of the hallmarks of the scientific method . . . M25 Charles Messier Categories of Messier Objects Star clusters Open Globular Nebulae Diffuse Planetary Galaxies Spiral M51 Elliptical Irregular A few Messier objects don't fit neatly into any of the categories noted above, e.g., M40, which is, in fact, a double star. M81 M82 sk yand tele scope .o r g * JUNE 2024 77 M52 M39 M27 M29http://skyandtelescope.org