Andromeda Galaxy - Collision, History, Location, Facts And Future!

Image credit : Adam Evans

For a very long time humans thought that Earth is the center of the Universe and the stars and planets revolve around the Earth in concentric circles. But then, Aristarchus came up with the new model around 240 BC and suggested that Sun was in-fact the center of Universe! For a long time we thought that the Milky Way consisted the whole Universe and all the bright dots we see are the stars that it contains.

Early Observation :

In 1764, Charles Messier labeled Andromeda Galaxy as M-31, which he stated that it was a nebula in the Milky Way! The first images of the Andromeda were taken by Issac Roberts in 1887. In 1920s, the Andromeda was a part of Great Debate between American astronomers Harlow Shapley and Heber Curtis. Curtis had spotted novae in Andromeda, and argued that it actually was a separate Galaxy.

The debate didn't concluded until 1925, when Edwin Hubble tried to determine the distance of Andromeda. Hubble determined a special kind of star known as Cepheid Variable - a star which helps to determine precise distances. Shapley previously determined that the Milky Way was 100,000 light years wide. With his calculation Hubble concluded that the Andromeda was too far to lie in the Milky Way, which proved that it was a galaxy on its own.

Facts About Andromeda Galaxy : 

NASA/JPL-Caltech/UCLA

Andromeda Galaxy is a spiral galaxy 2.5 million light-years away from Earth. It is located in the constellation of Andromeda. The Andromeda Galaxy has a diameter of 220,000 light-years compared to Milky Way's  estimated 150,000 light years, making it the biggest object in the Local Group. Andromeda is estimated to have around 1 trillion stars  which is more than twice the estimated number of stars in the Milky Way!

Andromeda Galaxy is formed by the collisions and mergers of the ancient protogalaxies about 10 billion years ago.

Andromeda and Triangulum had a very close passage 2 - 4 billion years ago. This increased the rate of star formation in the Andromeda Galaxy! But, over the past 2 billion years the star formation has decreased and reached even to a point of no-activity. 

Around 460 globular clusters - a group of stars - have been observed. One such is Globular One. It is too massive to be a globular cluster and hence considered as a remnant core of a dwarf galaxy absorbed by Andromeda.........Murderer!!!

ESA/Hubble

Collision With Milky Way : 

                  

The Andromeda Galaxy is approaching the Milky Way at a speed of whooping 110 km/s ..... not so whooping though! Both galaxies are predicted to collide in 4.5 billion years. It is also expected that the Triangulum Galaxy is also going to participate in the collision as well. And the cool thing is, we have a name for the final product - "MIKLDROMEDA" . 

The collision is predicted to last 2 billion years! The Mikldromeda is likely to be a elliptical galaxy.

Fate of Solar System : 

I know there are a lot of "doomsday thoughts" in our minds right now .... but, wait....

The stars are a lot far from each other. Look at the closest star we have, it is 4.2 light-years from us! The chances of head-on collision between star are very low. Some stars might collide while some might get stranded in the universe. 

Based on the current calculations there are 50% chances that the Solar System will  drift at a distance thrice than that it is in present. Well, there are 12%  chances that Sun will shoot out of the galaxy....quite high. But by then Sun will become a swollen red ball and Earth will be hell of a planet to live. Hope that we find some new place to move to........

 Our new home........

What do you think humans will be doing by that time? Extinct or Inter-planetary? Share in the comments down below.

Looking for Earth 2.0 - check this out then - Top 5 Exoplanets that can have alien life!