The birthplace of stars, the cosmic day cares, the home where toddler stars live out their younger days - nebulae. There are many different varieties of nebulae, and not all are the cosmic nurseries. Some mark the grave of long dead stars while others, hidden in the shadows, are only seen because of other objects that shine their light upon these hidden objects. While still others open our eyes to the cosmic sea of dust that we plow through every day while moving at thirty kilometers per second through the cosmic ocean.
Emission nebulae, the stellar nurseries of the cosmos, consist of the necessary ingredients to form baby stars, gas and dust. These nebulae are the vast breeding grounds for gas and dust to converge by the force of gravity to combine and heat up, eventually resulting in a hot, fresh, young star. The radiation from these young stars energizes the gas and dust around them so that they release light, hence the name emission nebula. The young stars also generate stellar winds which carve out immense caverns and large bubbles within the vast nebulous seas. The name emission nebula is host to many of the brightest nebulae in the night sky such as the Orion Nebula (M42*), and the Lagoon Nebula (M8*).
Another type of nebula, planetary nebula, marks the grave of long dead sun-like stars. Planetary Nebulae tend to be much smaller than emission nebulae because they only mark the grave of one star, about the size of the sun which is very small under cosmic terms, rather than the birthplace of many. As a sun-like star nears the end of its long life, it starts to shed its outer layers to the enormous cosmic sea. Lastly, in one final grasp at the cosmos, the star ejects its atmosphere into the surrounding space to form a beautiful planetary nebula.
There is still another nebula that marks the death of a more massive star, a supernova remnant. The name says it all, at the end of a massive stars life, it ejects itself into the surrounding sea at astonishing speeds. As the materials from the now dead star collide with the surrounding gas, it causes that gas to glow and as the supernova expands, it leaves behind its mark, a long, beautiful trail of glowing gas. One such nebula, the Veil Nebula, stretches across the field of view-ìì† of a telescope at a dark-sky-site.
Hidden, lurking, creeping in the shadows are Dark Nebulae which are only visible due to a foreground star field or nearby emission nebula. These are made of dark, churning patches of gas and dust that do not give off light that we can see. They appear silhouetted against their backdrop of stars, lit up by neighboring stars. When imaged, these nebulae are breathtaking and require many moments of admiration. It is likely that many of these nebulae still lay lurking in the shadows, hiding from the cosmic light.
Lastly, the reflection nebulae, the tons of gas and dust that move freely through the cosmic ocean, illuminated by nearby stars. One such reflection nebula doubles as a beautiful star cluster known as the Pleiades (M45) or the seven sisters being chased by the lust-driven hunter Orion. In the winter sky, by looking up, one may spot a fuzzy patch of sky with a few bright stars within. This fuzzy path is the Pleiades star cluster illuminating the surrounding dust forming a reflection nebula. These nebulae have opened our eyes to the amount of cosmic dust surrounding us.
Nebulae come in many different shapes and forms, some emit light while others hide from it. Many of these types of nebulae can be seen from the backyards of almost anywhere. Unfortunately, light pollution has blocked out many of these glorious cosmic nurseries that reside in their constellations, waiting for the next explorer to look up in astonishment at the great cosmic ocean waiting for us to lift up our sail and go forth, sailing into the vastness of the cosmos.

*the letter -ììòM' followed by a number stands for messier (messy-a) object number x, Messier was an astronomer that went looking for comets, at devised a catalog of objects that looked like comets, but were not
-ìì†the field of view of a telescope is the diameter of the circular area of sky that can be seen through a telescope using a given eyepiece