Why Is Our Galaxy Called the Milky Way?

(Last Updated On: July 19, 2019)
Why Is Our Galaxy Called the Milky Way?

What Is the Milky Way? 

The Milky Way is a barred spiral galaxy formation that is typical of many other galaxies in the Universe. It is neither the largest nor the oldest galaxy out there. But it is of particular significance to us human beings because it just happens to be home to both the planet and the solar system that we call home. 

In fact, the Milky Way is readily visible to the naked eye when looking up at the clear night sky from any of the darkest corners of the earth. It presents as a strip of condensed glowing arc cloaked in a film of white light that is actually made up of dust and gas particles. Meanwhile, the distinct band of concentrated light is the result of seeing a side-view of billions of other stars clumped together in the galaxy. The portion of the Milky Way that we can actually see is our galaxy, which is approximately six trillion miles long.

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The core of the Milky Way is composed of a supermassive black hole. A black hole is a gravitational field that is so powerful that it swallows up everything in its path, even light itself. Many arms composed of hundreds of billions of stars spiral out from the center, and just one of these stars is the earth’s own sun.  The Milky Way is estimated to be about 13.6 billion years old and has been recognized by Western Astronomy for thousands of years. 

How Was the Milky Way Formed?

The Milky Way originally came into being after the Big Bang, which occurred about 13.8 million years ago. Before this notably monumental event, the Universe was nothing but a hot, dense force. 

The Big Bang marks the time where the Universe began to expand and cool at a very rapid rate.  As the Universe cooled, bands of gas began to come together and form clumps, thus commencing the process of nuclear fusion that forms stars. As stars began to appear, they, in turn, were pulled together into groups by the forces of gravity, eventually forming their own separate galaxies. 

Some of the oldest star clusters, or globular clusters, in the Milky Way still date back to the formation of the galaxy. Meanwhile, the Milky Way continues to produce about seven new stars a year. Since its formation, the Milky Way has also developed a reputation for swallowing up other smaller galaxies. This is why it is often referred to as ‘cannibal galaxy’.

Why Is Our Galaxy Called the Milky Way?

The truth is that nobody knows who exactly is responsible for giving the galaxy its name, there is plenty of evidence as to how the name evolved. What is known is that the term “Milky Way” has been used in Western Astronomy for at least 2,500 years. 

What Is the Milky Way?

Suffice it to say, the galaxy has almost always been associated with that white creamy substance we know as milk. The current English name of the Milky Way Galaxy originates way back in the time of the ancient Greeks, who, upon looking up at this distinct light-colored patch highlighted against the dark background of the night’s sky, named the galaxy galaxias kyklos, or the “milky circle”. In addition, the Greek root word for the galaxy, Galactos, literally translates to “the milky thing in the sky”.

In fact, the Milky Way featured prominently in ancient Greek mythology. It is said that when Zeus brought his young half mortal half God son Hercules home to his wife Hera to breastfeed, Hera, being unimpressed with Zeus’s many affairs, pushed the illegitimate baby away. The result was a few drops of milk falling from her breast and assuming a permanent position in the night sky. 

The ancient Romans would also jump on the milk train by going on to dub this highly visible solar formation via lactea, which translates roughly to the “road of milk”. In the epic Roman poem Metamorphoses, the author Ovid states “There is a high track, seen when the sky is clear, called the Milky Way, and known for its brightness.”

The Milky Way is even immortalized in the title of a popular American candy bar invented by Frank Mars in 1923, which was named after the galaxy in honor of its trademark milky malted filling. There are various other cultural and linguistic translations of the Milky Way, most of which tend to consistently and predictably center around the common theme of milk.


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