The French astronomer Charles Messier was born on 26 June, 1730, and began his career at the age of 21. He was one of the first people in France to observe the predicted return of Halley's Comet in 1759, and became obsessed with comets - so much so that King Louis XV called him the 'comet ferret'. During his lifetime, Messier discovered 13 comets independently and shared credit for the discovery of six more. However, it is his catalogue of astronomical objects that has given him the lasting fame he sought as a comet hunter.

The catalogue started as a personal reference as he scanned the skies in his small telescope. The blurry objects he catalogued appeared identical to comets, but did not move in relation to the background stars the way a comet would. More than two centuries later, these 110 objects are still referred to as the 'Messier objects' and they include some of the most observed astronomical objects that lie outside of the solar system. Many of the Messier objects are observable with a pair of binoculars or a small telescope. Others require a more powerful telescope to make out details in the object.

Types of Messier Object

There are four main types of astronomical objects included in Messier's list - open clusters, globular clusters, galaxies and nebulae.

An open cluster is simply a grouping of stars in the sky. These stars often form from an associated cloud of gas and dust and can be quite young in age.

A globular cluster is a gravitationally-bound concentration of approximately 10,000 to one million stars, populating the halo or bulge of the Milky Way. Globular clusters are believed to be very old and formed from an earlier generation of stars.

A galaxy is a huge mass of stars and dust with upwards of several million stars. They are further classified by appearance, resulting in spiral galaxies which have a spiral structure; elliptical galaxies which are of ellipsoidal shape; and irregular galaxies which have irregular shapes.

A nebula is an interstellar cloud of gas and dust. There are two types in Messier's catalogue: diffuse nebulae, which are clouds of interstellar gas and dust; and planetary nebula, which are essentially shells of gas expelled by a star as it shrinks from a red giant to white dwarf.

The Objects

The following is a listing of all 110 objects found in the Messier catalogue:

• M1 - The Crab Nebula is a supernova remnant in the constellation of Taurus. The supernova which created it was first recorded by Chinese astronomers in July 1054 and the light from the explosion was visible during the day for nearly three weeks.
• M2 - Located in the head of Aquarius, this globular cluster shines at magnitude 6.5. It is easily visible in binoculars or a small telescope.
• M3 - Found in Canes Venatici, this globular cluster shines at magnitude 6.2. It is estimated to contain more than half a million stars and is a good target for binoculars or a small telescope.
• M4 - Located near the star Antares in Scorpius, this globular cluster shines at magnitude 5.6. In very dark skies it can be visible to the naked eye. One of the nearest globular clusters, it is another fine target for binoculars or a small telescope.
• M5 - Located in Serpens, this globular cluster shines at magnitude 5.6. It is thought to be one of the largest and oldest globular clusters.
• M6 - Known as the Butterfly Cluster, this open cluster of stars lies between the bow of Sagittarius and the tail of Scorpius. To the naked eye, it is visible as a patch of light, shining at magnitude 5.3, but a small telescope will resolve individual stars.
• M7 - Known as Ptolemy's Cluster, this object is an open cluster in the same area of Scorpio as M6. This grouping shines at magnitude 4.1.
• M8 - The Lagoon Nebula in Sagittarius is a diffuse nebula of magnitude 6.0 surrounded by a cluster of young stars. The radiation from the stars excites the gas of the nebula, causing it to glow - this is known as an emission nebula.
• M9 - Located in Ophiuchus, this globular cluster has a magnitude of 7.7 and is considered to be one of the nearer globular clusters to the galactic centre.
• M10 - Also located in Ophiuchus, this magnitude 6.6 globular cluster has an apparent diameter of half the full moon when observed through a telescope.
• M11 - The Wild Duck Cluster is an open cluster in Scutum which shines at magnitude 6.3. Containing more than 2,900 stars, this cluster makes a challenging target for a small telescope to resolve.
• M12 - This magnitude 6.7 globular cluster in Ophiuchus is an apparent twin to its neighbour M10, though it is a bit fainter and larger.
• M13 - The Great Hercules Globular Cluster is a famous globular cluster visible to the naked eye under dark skies in the constellation of Hercules. With binoculars or even a small telescope, you should be able to see some individual stars. With larger telescopes, you will see more and more stars in the central core.
• M14 - Another globular cluster in Ophiuchus, this one shines at magnitude 7.6 and is slightly elliptical in shape.
• M15 - This globular cluster in Pegasus is believed to be one of the most dense star groupings in the Milky Way. It shines at magnitude 6.2.
• M16 - An open cluster in Serpens which shines at magnitude 6.5. These stars are associated with the Eagle Nebula, an emission nebula thought to be responsible for the creation of the stars in this cluster.
• M17 - Known as the Omega Nebula, this emission nebula in Sagittarius shines at magnitude 7.0. It is also known as the Swan Nebula, the Horseshoe Nebula, or (especially in the southern hemisphere) the Lobster Nebula.
• M18 - An open cluster in Sagittarius of magnitude 7.5; a small telescope will show about a dozen fairly bright stars.
• M19 - A small, elongated globular cluster in Ophiuchus of magnitude 8.5, this object lies east of Antares in the Milky Way.
• M20 - Known as the Trifid Nebula, this nebula has diffuse and emission parts. Shining in the constellation of Sagittarius at magnitude 9.0, it sits to the north-west of M8, the Lagoon Nebula.
• M21 - An open cluster in Sagittarius which shines at magnitude 6.5, this object is situated close to M20, the Trifid Nebula.
• M22 - Shining at magnitude 5.1, this is the brightest globular cluster in the northern sky. Located in the constellation of Sagittarius, this object is visible to the naked eye as long as the observer does not live at an extreme northern latitude.
• M23 - This open cluster is a great target for binoculars and small telescopes. Lying in Sagittarius, it shines at magnitude 6.9.
• M24 - This object is not a 'true' deep sky object. Rather, it is a tunnel through the galactic dust allowing us to see a bright patch of stars. Shining at magnitude 4.6 in Sagittarius, this object is easily visible to the naked eye, but there are so many other clusters and Messier objects in the area that it is sometimes difficult to spot.
• M25 - Located in Sagittarius and shining at magnitude 6.5, this open cluster is conspicious in a small telescope or binoculars.
• M26 - An open cluster in Scutum shining at magnitude 8.0, this object doesn't stand out like its neighbour M11. However it's still a good target, with about 25 stars visible in a medium to large-sized telescope.
• M27 - The Dumb-bell Nebula is a planetary nebula located in Vulpecula and shining at magnitude 7.5. It is visible with large binoculars or a small telescope, though a larger telescope will show more detail.
• M28 - Shining at magnitude 6.8 in Sagittarius, this globular cluster appears smaller and less impressive than its neighbour M22. However, it still makes a good target for binoculars or a small telescope.
• M29 - A rather unimpressive open cluster of magnitude 7.1 in the constellation of Cygnus. Astronomers have found that interstellar dust and gas lie between us and the stars, causing them to appear dimmer than they should. Without the dust, this cluster would be easily visible to the naked eye!
• M30 - Located in Capricornus and shining at magnitude 7.2, this globular cluster makes a fine target in a small telescope. It has an extremely dense core which is impossible to resolve into individual stars without a large telescope.
• M31 - The Andromeda Galaxy is found in the constellation of Andromeda and is a fuzzy patch of light visible to the naked eye on dark nights. It is the nearest spiral galaxy to our own Milky Way galaxy. Binoculars or a small telescope will show some detail and two companion galaxies (M32 and M110).
• M32 - This satellite to the Andromeda Galaxy is found to the south of M31. Binoculars or a small telescope are required to view this elliptical galaxy which will appear bright and circular in them.
• M33 - The Triangulum Galaxy shines at magnitude 5.7 in the constellation of Triangulum. This spiral galaxy can be seen with the naked eye under exceptionally good conditions; for most people, it is the most distant object visible to the naked eye. It is outstanding in good binoculars, but as its considerable total brightness is distributed quite evenly over an area of nearly four times that covered by the full Moon, its surface brightness is extremely low.
• M34 - An open cluster which shines at magnitude 5.5 in Perseus, this object can be visible with the naked eye in dark skies, but a small telescope or pair of binoculars will show many of the stars which are scattered over an area as large as the full moon.
• M35 - Located in Gemini and shining at magnitude 5.3, this open and nearly circular cluster with uniform stellar distribution is visible to the naked eye near the three 'foot stars' of Gemini. The slightest optical instrument will resolve the brighter stars and make it a splendid view at low magnifications.
• M36 - This open cluster in Auriga shines at magnitude 6.3. It is composed of the same type and size of stars as is found in M45, but it lies ten times further from us than The Pleiades.
• M37 - The brightest of the three open clusters in southern Auriga (M36 and M38 are the others), this object shines at magnitude 6.2.
• M38 - Located just to the north-west of M36 in Auriga, this open cluster shines at magnitude 7.4, making it the faintest of the open clusters in this constellation.
• M39 - Located to the east and north of the bright star Deneb in the constellation of Cygnus, this magnitude 5.2 open cluster is visible on dark nights and is excellent in binoculars. It is spread across a large swath of the sky, so low power viewing is needed in telescopes.
• M40 - A double star located in Ursa Major which shines at magnitude 8.4. There is some speculation that Messier included this in his catalogue to 'pad' the number of objects as it is not one of the typical fuzzy patches of light that could be mistaken for a comet.
• M41 - Shining at magnitude 4.6, this open cluster in Canis Major is an excellent target for binoculars and small telescopes. It lies dues south of Sirus, the brightest star in the northern sky, and contains more than 100 stars scattered over an area about the size of the full moon.
• M42 - The Great Orion Nebula is easily visible to the naked eye, shining at magnitude 4.0 in the constellation of Orion. It is represented as the sword hanging from Orion's belt. This object is the brightest diffuse nebula in the sky and is an interstellar nursery where new stars spring to light, energizing the gas in the nebula causing it to glow. This object is a must-see in any instrument you can find - it is magnificent in both binoculars and telescopes!
• M43 - This diffuse nebula is actually a part of M42 in Orion; however, it is separated from the main nebula by a lane of dark dust. It shines at magnitude 9.0 and is small and round in shape.
• M44 - The Beehive Cluster is an easily visible open cluster of magnitude 3.7 in the constellation of Cancer. It is also known as Praesepe, which is Latin for 'manger'. A small telescope will reveal around 40 stars.
• M45 - The Pleiades or Seven Sisters is an open star cluster with seven naked-eye stars in the constellation of Taurus. Viewing with binoculars or a small telescope will reveal dozens of stars. The cluster's Japanese name is Subaru, which is why the car company uses these stars in its logo.
• M46 - This open cluster shines at magnitude 6.0 in the constellation of Puppis. This was the first object added to Messier's original list of 45 objects. A telescope will reveal many stars in this grouping which is slightly less than the width of a full moon.
• M47 - Visible to the naked eye under dark skies as a fuzzy patch in the constellation of Puppis, this open cluster shines at magnitude 5.2 and resolves into stars with a telescope or pair of binoculars, resolving some of the individual stars scattered over an area the size of the full moon.
• M48 - This open cluster located in Hydra is bright at magnitude 5.5, and is visible to the naked eye under good conditions. A pair of binoculars or a small telescope will show a large group of about 50 stars brighter than magnitude 13.
• M49 - One of the brightest members of the Virgo group at magnitude 8.5, this elliptical galaxy is visible as a clear glowing patch in a medium telescope.
• M50 - This open cluster shines at magnitude 6.3 in Monoceros. It is a relatively small cluster spread over an area half the size of the full moon.
• M51 - The Whirlpool Galaxy in Canes Venatici shines at magnitude 8.4. This spiral galaxy is interacting with its small companion galaxy. This galaxy is a great target and one you'll never forget if the sky is dark, but it is quite sensitive to light pollution, which easily makes it fade into the background. Under very good conditions, suggestions of its spiral arms can be seen with a four-inch telescope at low magnification.
• M52 - Located in the constellation of Cassiopeia, this open cluster shines at magnitude 7.3. It is a nice cluster against the background of the Milky Way star field.
• M53 - This globular cluster in Coma Berenices shines at magnitude 7.6 and is one of the furthest globular clusters from the galactic centre.
• M54 - Located near the eastern star at the bottom of the 'teapot' in Sagittarius, this globular cluster shines at magnitude 7.6. It is a very tight globular cluster and only large telescopes can resolve individual stars near its core. It makes an easy target for a small telescope or pair of binoculars, but can be easily overlooked because of its small size.
• M55 - This large globular cluster (almost two-thirds the size of the full moon) looks very much like an open cluster. Located in Sagittarius due east of M54, this object shines at magnitude 6.3 and is relatively easy to find in binoculars or a small telescope using low power.
• M56 - Located halfway between the double star Alberio in Cygnus and M57 in the constellation of Lyra, this dim globular cluster shines at magnitude 8.3.
• M57 - The Ring Nebula in Lyra is a planetary nebula which shines at magnitude 8.8. This object is one of the most viewed deep sky objects and has been described as a 'prototypical' planetary nebula. It is a challenge to find, but seeing it will give you a glimpse of the future fate of our own Sun.
• M58 - This spiral galaxy in Virgo is one of the brightest galaxies of its type in the Virgo group, shining at magnitude 9.7. Forget the binoculars for this one, you'll need a telescope if you want much chance of glimpsing this object.
• M59 - An elliptical galaxy of magnitude 9.6 in the Virgo group, it is believed to have a mass of only one quarter that of M60. Another telescopic target only.
• M60 - An eliptical galaxy, magnitude 8.8 in the Virgo group. Even though it is elliptical it seems completely rounded and looks like a fuzzy star through a medium-sized telescope.
• M61 - A faint spiral galaxy, magnitude 9.7, which appears to be one of the larger galaxies in the Virgo group. It is estimated to be about the same size as our own Milky Way.
• M62 - Located in Ophiuchus, this magnitude 6.5 globular cluster is one of the closest to the galactic core. A large telescope will reveal that the globular cluster's core is slightly off-centre due to the tidal influences of the galactic core.
• M63 - The Sunflower Galaxy is located in Canes Venatici and shines at magnitude 8.6. This galaxy is believed to belong to the same group as M51.
• M64 - Known as the Blackeye Galaxy or the Sleeping Beauty Galaxy, this spiral galaxy in Coma Berenices is so named because of a large black lane of dust which obscures a portion of the galaxy's stars. It shines at magnitude 8.5 and large telescopes are needed to see any kind of detail.
• M65 - A spiral galaxy in Leo which shines at magnitude 9.3, this object is close to M66 and is gravitationally influenced by it, though this galaxy shows no signs of deformation.
• M66 - This is a spiral galaxy of magnitude 8.9 in Leo, halfway between Denebola and M96. A neighbour of M65, this object has a slightly larger core, and displays some distortion in its spiral arms as viewed through a large telescope.
• M67 - An open cluster on the verge of naked eye visibility at magnitude 6.1, M67 is located in Cancer just to the west of the eastern star at the bottom of the constellation. It is a good target for binoculars and a wide-field small telescope, as the cluster is scattered over an area the size of the full moon.
• M68 - Located in Hydra, this magnitude 7.8 globular cluster is small and tight. In most small telescopes it will appear as a small fuzzy star. Larger instruments are needed to resolve individual stars.
• M69 - This globular cluster in the constellation of Sagittarius shines at magnitude 7.9. Like its neighbour M70, this globular cluster is small and one of the faintest in Messier's catalogue.
• M70 - Slightly larger and brighter than its neighbour M69, this globular cluster in Sagittarius shines at magnitude 7.6. This cluster is located to the west of M54 and to the southeast of M69.
• M71 - This globular cluster was classified as an open cluster in some circles for a long time, but it is, in fact, a loose globular cluster. Shining at magnitude 8.2 in the constellation of Sagitta, it is easy to find in good binoculars. Medium-sized telescopes are required to resolve the centre of the cluster.
• M72 - A faint globular cluster in Aquarius shining at magnitude 9.3, a four-inch telescope will show it as a fuzzy patch of light. An eight-inch telescope will begin to resolve some of the stars on the outer edges of this object. It is one of the most remote globular clusters in Messier's list.
• M73 - Located in Aquarius, this dim grouping of four stars forms an open cluster of magnitude 9.0. Located just to the west of M72, this object is contentious as astronomers aren't sure if the stars are related or if they are just a random grouping.
• M74 - This faint spiral galaxy in Pisces shines at magnitude 9.4. Very good conditions are needed to see more than the bright centre nucleus of this galaxy. A four-inch telescope will begin to show the spiral arms under perfect conditions, though larger telescopes are usually needed.
• M75 - This globular cluster in Sagittarius shines at magnitude 8.5. It is one of the more distant Messier globular clusters and is very tight and compact.
• M76 - Among the faintest of the Messier objects, this planetary nebula shines at magnitude 10.1 in the constellation of Perseus. It is known as the Little Dumb-bell Nebula (the most common name), Cork Nebula, Butterfly Nebula, and Barbell Nebula.
• M77 - Among the largest galaxies in Messier's catalogue, this face-on spiral galaxy is bright enough at magnitude 8.9 that a small telescope will spot it rather easily under dark skies. Located in the constellation of Cetus, larger instruments will show good detail.
• M78 - Located north of the easternmost star in Orion's belt, this diffuse nebula shines at magnitude 8.3 This object doesn't get its due because of the more spectacular M42 located to its south.
• M79 - This beautiful globular cluster is located in the 'wrong' part of the sky in the constellation of Lepus. Most globular clusters can be found near the galactic centre, but this one lies in the opposite direction. It shines at magnitude 7.7.
• M80 - Located in Scorpius, this globular cluster lies almost exactly halfway between Antares and Graffias. Shining at magnitude 7.3, this object looks exactly like a comet in a small telescope, and larger instruments are needed to resolve individual stars.
• M81 - This spiral galaxy in Ursa Major is also known as Bode's Galaxy. It is one of the brightest in the northern sky, shining at magnitude 6.8, and it is easily viewable with a small telescope - some observers have even claimed to see this galaxy with the naked eye in extremely dark skies.
• M82 - The Cigar Galaxy in Ursa Major shines at magnitude 8.4. This irregular galaxy, a strong radio source, lies to the north of M81, and they are part of the same group.
• M83 - Shining at magnitude 7.6 in the constellation of Hydra, this spiral galaxy appears as a fuzzy patch in small and medium telescopes. Large instruments are able to resolve the spiral arms as well as some individual stars. In April 2008 it was announced that new stars have been discovered in the otherwise barren outskirts of the galaxy.
• M84 - This elliptical galaxy in the constellation of Virgo is a difficult target at magnitude 9.1. It is a member of the Virgo group of galaxies.
• M85 - Found in the constellation of Coma Berenices, this elliptical galaxy is another difficult target at magnitude 9.1. It is the northernmost member of the Virgo group of galaxies listed by Messier.
• M86 - This dim elliptical galaxy in the Virgo cluster shines at magnitude 8.9. It is small and dim, making it one of the more difficult objects in Messier's catalogue to observe.
• M87 - This elliptical galaxy in the Virgo cluster shines at magnitude 8.6. It is the brightest of the galaxies in this cluster and is a very intense radio source.
• M88 - This well-defined spiral galaxy of the Virgo group shines at magnitude 9.6. Though it is member of the Virgo group, this galaxy actually lies in the constellation of Coma Berenices.
• M89 - Located in Virgo and shining at magnitude 9.8, this elliptical galaxy is another member of the Virgo group. In a large telescope it appears nearly perfectly circular.
• M90 - Shining at magnitude 9.5, this spiral galaxy in the constellation of Virgo is one of the larger spiral galaxies that are members of the Virgo group
• M91 - This spiral galaxy in Coma Berenices is actually classified as a barred-spiral galaxy because of a large band of stars and dust extending across the centre of the galaxy. Shining at magnitude 10.2, this member of the Virgo group will display a hint of this barred structure in a small telescope under medium power, if conditions are dark enough to be able to see the galaxy at all.
• M92 - This globular cluster in Hercules shines at magnitude 6.4, only slightly dimmer than the more famous M13. Though it is less bright than M13, it is smaller as well so it looks great in binoculars or large telescopes.
• M93 - Located in Puppis, this magnitude 6.0 open cluster is one of the smaller clusters in Messier's catalogue, but it is also one of the brightest. Binoculars or a small telescope will show dozens of stars in this grouping.
• M94 - This spiral galaxy in Canes Venatici shines at magnitude 8.2. It appears face-on and is bright enough to see a fuzzy patch with a small telescope or more detail in a large instrument.
• M95 - This barred-spiral galaxy is found in the constellation of Leo and it shines at magnitude 9.7. It will take a large telescope to see any details on this faint, small and distant galaxy.
• M96 - At magnitude 9.2, this spiral galaxy is the brightest of the so-called M96 group of galaxies containing M95 and M105. All three galaxies are located in the constellation of Leo.
• M97 - The Owl Nebula in Ursa Major is one of the fainter objects in Messier's catalogue, shining at magnitude 9.9. This planetary nebula requires a large telescope to see the 'eyes' which gave this object its nickname. A smaller telescope will show a fuzzy disk, but no details.
• M98 - This spiral galaxy in the constellation of Coma Berenices is faint (magnitude 10.1) and difficult to observe as it is edge-on to our line of sight. It is a member of the Virgo group of galaxies.
• M99 - Located in Coma Berenices, this magnitude 9.9 spiral galaxy is one of the members of the Virgo group. While it has a low visual magnitude, it is a good target for a medium telescope.
• M100 - Shining at magnitude 9.3, this spiral galaxy located in Coma Berenices is one of the brightest of the Virgo group. A small telescope or binoculars reveal the central regions of this galaxy as faint elliptical patch of uneven texture. Under good observing conditions, suggestions of the inner spiral arms can be glimpsed in telescopes higher than four inches in aperture.
• M101 - The Pinwheel Galaxy in Ursa Major is a spiral galaxy which shines at magnitude 7.9. A small telescope will show the bright central regions of this galaxy. The arms begin to be visible in telescopes with more than four inches in aperture.
• M102 - This is the most controversial object in Messier's catalogue. Some suspect that he mistakenly observed M101 again and wrote down the wrong coordinates in his book. Others speculate that this object is a spiral galaxy seen edge-on in the constellation of Draco which shines at magnitude 9.9.
• M103 - Located in the constellation of Cassiopeia, this magnitude 7.4 open cluster contains about 40 stars which can be seen under low power with a good medium telescope.
• M104 - The Sombrero Galaxy is a large spiral galaxy in Virgo which we view nearly edge-on. A large telescope will clearly show the dark dust lane responsible for the 'brim' on the hat.
• M105 - Located in Leo in the M96 group of galaxies, this elliptical galaxy shines at magnitude 9.3 and lies to the north of both M95 and M96.
• M106 - This spiral galaxy in Canes Venatici shines at magnitude 8.4. A large telescope will show details of its long dusty arms, and it will appear as a faint smudge in small and medium instruments.
• M107 - A globular cluster in Ophiuchus which shines at magnitude 7.9. Appearing as a tight fuzzy star in small telescopes, a larger instrument is required to show details of individual stars.
• M108 - Shining at magnitude 10.0, this spiral galaxy in the constellation of Ursa Major makes a fair target for even small instruments, as it shows more detail than one would expect. Larger telescopes are better at resolving this edge-on galaxy.
• M109 - Located in Ursa Major, this spiral galaxy shines at magnitude 9.8. Small telescopes will show the bar structure extending from its centre, making it appear pear-shaped. Larger instruments will show much more detail.
• M110 - This satellite to the Andromeda Galaxy is found slightly to the north of M31. Binoculars or a small telescope are required to view this elliptical galaxy, which will appear bright and slightly elongated.

Picture of M1 courtesy of NASA