Our approaching neighbor, Andromeda Galaxy

What is the Andromeda Galaxy?

Before I begin, I would like to state why I changed this week's topic (it was supposed to be about wave function collapse), I feel like I need to discuss more topics before getting into a complex topic which is why I will delay it till I build more base-knowledge. At the center lies a supermassive black hole, commanding the stars to follow its curvature and causing them to follow set paths. As we discussed previously, galaxy cluster's motions are affected by Dark Matter. M31, AKA Andromeda Galaxy is a barred spiral galaxy (galaxy types in the image below) that was discovered in the 1920s by famous scientist E.Hubble. Compared to our galaxy (The Milky Way), Andromeda is much denser with around 1 trillion stars meanwhile TMW sits at 300-400 million. It has been theorized that Andromeda formed around 5 to 9 billion years ago by a collision of two smaller galaxies. Did you know that the galaxy appears 6 times wider than the moon in the sky, according to astronomytrek.com, "... but it may come as a surprise to most people that the Andromeda galaxy appears six times wider than the full Moon in the night sky. Even the naked-eye portion, which appears as a cloud of faint light, is about the size of the Moon (0.5 degrees of the sky), while 10×50 binoculars will reveal a much larger image. Using an 8-inch (200mm) telescope, M31 presents a spectacular sight with its diffuse dust lanes stretching out from its bright center, and if these vast spiral arms are included, the Andromeda Galaxy would cover around 20 degrees of sky or 40 full Moons."

Andremoda size in comparasion to the moon, Source : me.me

Types of galaxies, Source : Socratic.org

The Future of our Residence 

Andromeda galaxy is heading straight for us,  approaching at approximately 110 km/s. Before you wonder what this will mean for Earth, scientists believe that Earth won't be affected as much as you think. According to https://www.businessinsider.com/, "An epic war is coming between our home galaxy and the Andromeda Galaxy, which is currently racing toward us at a speed of 250,000 mph. Astronomers estimate that 3.75 billion years from now, Earth will be caught up amid the largest galactic event in our planet's history, when these two giant galaxies collide. Luckily, experts think that Earth will survive, but it won't be entirely unaffected. The collision will unfold right in front of us, changing the night sky to look like nothing any human has seen before." The battle will continue for billions of years as the supermassive black holes get close enough to merge, The collision will form an elliptical type of galaxy containing the remnants of both galaxies. Imagine the view, multiple explosions and a variety of new stars will light up our night sky and will be an amazing wonder to observe, but what I believe is even more beautiful is the night sky view right before the collision, we will have an amazing close-up view of the galaxy.

Image of the simulation of the collison, the simulation's link and Source: https://www.youtube.com/watch?v=yi-2ySsWSAs

Sub Topic : Andromeda Discovery Story

Andromeda was initially misidentified until Edwin Hubble successfully confirmed it to be a galaxy. According to theplanets.org, "The first supernova observed outside the Milky Way was S Andromedae. Also, it remains the only supernova event that was ever observed in the Andromeda Galaxy. It is also called Supernova 1885 after the year it was seen. At the time, the distance of the Andromeda Galaxy was not yet fully known. It was thought to be just another nearby object in the Milky Way that they called “Nova 1885.”Charles Messier gave the designation M31 to Andromeda in 1764. And even by then, astronomers had given it some interesting descriptions. Abd al-Rahman al-Sufi called it a “nebulous smear” and for some, it was the “little cloud.” French philosopher Pierre Louis Maupertuis considered it an “island universe.” William Herschel, on the other hand, noted that it is the closest “great nebula” to us. One of the earliest photographs of Andromeda was taken by Isaac Roberts in 1888. Though, at this time, it was still considered a “spiral nebula,” a field for the formation of new stars."