The Andromeda Galaxy is one of the most fascinating objects in the night sky. It is a spiral galaxy that is about two and a half million light years away from Earth. Despite being so far away, it can be seen with the naked human eye. The Andromeda Galaxy is also famous for being one of the galaxies that will collide with our Milky Way in the near future. This collision will create a new galaxy altogether. In this article, we will explore the Andromeda Galaxy and what the collision could mean for life as we know it.
The earliest record of the Andromeda Galaxy appears in a book called “Book of the Fix Stars” which was written in the year 964 by Persian astronomer Abid Al-Rahman Al-Sufi. French astronomer Charles Messier mentioned it in his famous catalogue “De Nibilus Des Amadetois”. The Andromeda Galaxy was initially believed to be just another one of the millions of so-called nebulae in space and wasn’t really considered to be of much significance at the time.
British astronomer William Herschel was one of the first astronomers to take an interest in the Andromeda Galaxy. He noted the faint reddish hue in the core region of the galaxy. The first ever photographs of the galaxy were taken in 1887 by Isaac Roberts from his private observatory in Sussex. The supposed nebula M31 was factored into the great debate between astronomers Heber D Curtis and Harlow Shapley in regards to the scale of the universe. Curtis was of the opinion that the spiral nebulae like the Andromeda Nebula or Messier 31 were actually completely different galaxies and that the Milky Way was just one galaxy among many. On the other hand, Shapley strongly disagreed, arguing that the nebulae were simply spiral pockets of gas and there were no galaxies, just simply the universe that is the Milky Way.
The answer to this question would arrive in the form of one of the most important discoveries in astronomy, made by none other than Edwin Hubble himself. Up until the 20th century, our perception of space and what lies in the great skies above was extremely limited and fell only within the bounds of the Milky Way. Hubble’s curiosity led him to the Mount Wilson Observatory in California right to the world’s largest telescope at the time, the 100-inch Hooker telescope. Here Hubble used the telescope to observe faint fuzzy cloud-like patches of light that were then broadly labeled as nebulae. When he turned the Hooker telescope in the direction of the Andromeda constellation, it completely transformed the field of cosmology.
During his observations, he uncovered his first Cepheid variable star, a type of star used to measure out distances in space based on how it changes and varies in brightness. By charting the various changes in the star’s brightness, he soon discovered that the Cepheid variable stars in Andromeda were actually much farther away than those lying in the Milky Way. After studying this contrast in distance, he came to believe that the so-called Andromeda Nebula was not just some great nebula floating out there in space, but rather another whole entire galaxy in its own right.
In conclusion, the Andromeda Galaxy is a fascinating object that has captured the imagination of astronomers for centuries. Its collision with the Milky Way is an event that will shape the future of our galaxy and could have a significant impact on life as we know it. With our advanced space technology, we may one day be able to explore this galaxy and uncover more of its secrets.
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