Milky Way Galaxy

The Milky Way Galaxy, also known as the Milky Way or the Galaxy, is a galaxy which contains the Solar System in which Earth exists. The Milky Way is classified by astronomers as a “barred spiral galaxy” and is located within a group of other galaxies called a Local Group of galaxies. While the Milky Way is large, to give an idea in relative terms, the Milky Way is just one of billions of galaxies that have been observed by scientists and astronomers. Technically, many people believe that the term “Milky Way” should be used to describe the band of light that the galaxy creates in the night sky, as opposed to the term “Milky Way Galaxy”, which should be used to refer to the galaxy itself.

The Milky Way Galaxy from Earth:
From Earth, the view of the Milky Way Galaxy shows a hazard white band of light which arches across the celestial sphere. The pale light from the Milky Way is caused by a group of stars and other material that is contained within the galaxy body. Judging locations of it is easy when observed in relation to a constellation. The Milky Way Galaxy looks brightest when observed from the direction of the constellation of Sagittarius when looking into the center of it. It spreads further north to the constellation of Cassiopeia and south to the constellation of Crux. The fact that the Milky Way appears to divide the night sky into two separate hemispheres indicates that the solar system that contains Earth is located very close to the galactic plane.

In urban areas and even suburban areas, it is extremely difficult to see the Milky Way because of its very low surface brightness. The reason for the low surface brightness is due to the interstellar medium, which in turn makes it extremely difficult to see the bright galactic center of it.

Characteristics of the Milky Way:
The “stellar disk” of the Milky Way Galaxy is about 100,000 light years in diameter and is about 1,000 light years thick. Astronomers believe that the galaxy is home to approximately 200 to 400 billion stars. The reason why scientists are unsure of the exact number is because of the large amount of low-mass stars, which are sometimes not classified as stars at all. This may seem like a lot of stars, but speaking once again relative terms, the neighboring galaxy, Andromeda, trumps the Milky Way, and has about one trillion stars. The distance between stars increases as one would travel further from the center of the galaxy. The surrounding area of the stellar disk contains a thick band of gas which is estimated to have a thickness of about 12,000 light years. In addition, many recent observations proves that the Milky Way is much larger than previously thought and may be similar in size to Andromeda.