Charles Messier (1730-1813)

Was an 18th century French astronomer who was famous at the time as a "Comet Hunter".  He set out to catalogue commonly mistaken objects that were thought to represent comets.  He catalogued roughly 110 objects that later due to technological advances were identified as Galaxies, Clusters of stars both grouped and open known as Globular Clusters and Open Clusters, as well as Nebulae of various types. 

Getting to view these celestial objects is generally considered an amature astronomers rite of passage in astronomy circles...          

.....Even tougher is the task of imaging them.

 

 

Globular Clusters:

These are compact groupings of stars that can be comprised of thousands of stars.

 

 M13

 

Open Clusters:

These groupings of stars are loosely held together in the same area of space, while these generally will be quite smaller in their populations they tend to show the most color of the two types of clusters.

 

 

Galaxies:

Like our own, they are comprised of Stars, Gases, Dark Matter, Dark Energy, Planets, Comets, all sorts of other phenomena, and generally a Black hole at its center.

 

 

Nebulae:

Giant gas clouds that generally were produced from dying stars, are known to be the nurseries of future stars.  The hot gasses get compacted due to gravity and disturbed by time/space forces that cause new Nuclear Fusion reactions to begin, forming new stars.  From our vantage point they are brilliant displays of color, but they shroud a very hostile environment to say the least.