Essay On Nebulae

Nebulae are cosmic clouds of dust and gas floating in space. The word nebula is Latin and means cloud. Originally the word nebula referred to any extended astronomical object, not including comets, planets, or satellites. But over time the word nebula became reduced to mean interstellar cloud of dust and gas. Calling it that does not do a nebula justice. Most nebulae are commonly made up of hydrogen and helium gasses, dust, and plasma. Nebulae are the building blocks of our universe; they contain all the things stars need to form. Scientists classify nebulae in to one of two major categories; bright and dark. From there they narrow it down more to planetary nebulae, emission nebulae, reflection nebulae, dark nebulae, and supernova remnants. Bright nebulae are close enough to stars to glow, and dark nebulae are to far away from stars to do so. Dark nebulae are only visible if a star cluster or other bright object provides a backdrop. Sometimes they are part of a bright nebula. A good example of this phenomenon would be the Trifid Nebula. It is a bright nebula divided into three sections by dark “alleys” spanning across it. Getting down into the smaller categories, planetary nebulae form when a star cannot support itself by fusion reactions in its center. Gravity forces the outer layers of the sun in on its core, making the insides heat up and condense. The heat from the center blows the outsides away in a stellar wind over a few thousand years. When the star finishes the only thing left of it is the core. The core then heats the distant gasses and they glow because of this. Despite planetary nebula being called planetary nebula, planets have nothing to do with them. They are a very common nebula in our galaxy, as there are an es...

... middle of paper ...

...began to classify and catalogue objects in space that were not stars. Instead of using names he gave them a number. For example, the Ring Nebula was, and is, classified as Messier fifty seven or M57. The very first object Mr. Messier classified was the Crab Nebula in Taurus, which Mr. Messier designated Messier one (M1.) There are now one hundred and nine Messier objects recognized as M102 was admitted to be M101 re-observed. Then in the 19th century amateur astronomers began to name all of the Messier objects. The astronomers named most of the nebulae after the shape they resembled, so that is how the Dumbbell and Owl Nebulae got their names. Some nebulae are named after the constellation they are part of, like the Orion Nebula in the Orion Constellation.

While scientists and astronomers discover, classify, and catalogue nebulae they are quite pretty. Nicknamed