The Milky Way is our home galaxy. If you did not know that, then you are living under a rock. However, if you think that the Milky Way is the only galaxy in the entirety of the Universe, then you are highly mistaken. While the Milky Way does house our solar system, it is nothing compared to the million other galaxies in the Universe in terms of diameter, mass, distance from Earth, number of astronomical bodies, and so on. Scroll down to find out which are the ten most massive galaxies in the Universe apart from our Milky Way. 

Andromeda Galaxy

You can call it M31, Messier 31, NGC 224, or Andromeda Galaxy. This massive spiral galaxy got its name from mythological princess Andromeda. While not the nearest galaxy, it is the most massive spiral galaxy near the Milky Way. Also, it is 1.76 times more massive than our home galaxy, with a diameter of 220-kilo light-years (kly). This 2.537 million light-years away a galaxy was discovered in 1765 and is the last celestial body in the Universe that we can see from naked eyes. Astronomers believe that in around 4.5 billion years, Milky Way and Andromeda will collide to form a new galaxy. 

Tadpole Galaxy 

In the northern constellation Draco lies a distinct tadpole-shaped like a disrupted spiral galaxy –  the Tadpole Galaxy, first discovered in 1781. It is 420 million light-years away from us and features the most dramatic string of stars, which is 280000 light-years long. Scientists speculate that this massive galaxy got its tadpole-like shape after colliding with a neighboring galaxy. They also predict that as the famous tail of the galaxy grows older, it will absorb in the main spiral. 

ESO 444-46 Galaxy 

The next galaxy in this list of ten of the most massive galaxies in the Universe is as massive as 10000 Milky Way galaxies, with the size of 402200 light-years, which is why ESO 444-46 definitely deserves a spot here. It also has the largest concentration of matter that is known to man till date. This galaxy is one of the most beautiful galaxies out there as it is the brightest member of Abell 3558 galaxy cluster that is located in the Shapley Supercluster. ESO 444-46 is an elliptical galaxy, which was first noticed in the year 1834 and is 640 million light-years away.  

Condor Galaxy

Discovered by John Herschel, an English astronomer, on 27 June 1835, Condor Galaxy is our next pick with a mass of 522 kly (kilo light year). Also known as NGC 6872, the Condor Galaxy is the largest spiral galaxy in the Universe. What makes this galaxy even more unique is its long arms, which is a big attribute in the Condor Galaxy being the largest known spiral galaxy. NGC 6872 is 212 million light-years away from Earth and is in an ongoing collision with another galaxy IC 4970. 

Comet Galaxy 

Found using the Hubble Space Telescope, Comet Galaxy is a spiral galaxy, which is located roughly 3.2 billion light-years away. It rushes through the Abell 2667 galaxy cluster at a speed of 3.4 million kilometres/ hour just like a comet. This shows a tail that is 600000 light-years lengthy. Comet Galaxy is one of the more recent discoveries, founded in 2007 only. This galaxy is very important to the astronomers as it has been very valuable in providing insights about what causes these strong and vibrant galaxies to shrink and become “gas-poor”. 

UGC 2885

Rivalling the Comet Galaxy is UGC 2885, an unbarred spiral galaxy in the constellation Perseus, with a mass of 832000 light-years, which is estimated to be 8 times the diameter of our home galaxy Milky Way. While it is not confirmed, this galaxy may be a member of the Pisces-Perseus supercluster. You can only observe the galaxy by infra-red wavelengths. Scientists discovered this galaxy in 2002, 313 million light-years away, and believe that instead of collisions of several small galaxies, it was formed by gas, which raises many questions. 

ESO 306-17

The fourth most massive galaxy in our observant Universe known to the astronomers is ESO 306-17 with a diameter of 1 million light-years. Its location is one of the most interesting facts about this galaxy. Located in the Columbia constellation, this fossil group giant elliptical galaxy lies in a fairly abandoned part of the space, surrounded by hot gas and dark matter. Scientists think that ESO 306-17 absorbed all the galaxies in its neighborhood and now sits almost alone 0.5 billion light-years away. 

Abell 2261 – BCG

3 billion light-years away from Earth in the Hercules constellation, lies the third most massive galaxy in our Universe. It is also the largest and brightest galaxy in the galaxy cluster of Abell 2261. It also has ‘the most massive galaxy core’ till date, which is quite distinct in its appearance compared to the center of most other galaxies. This massive galaxy with a diameter of 1000000 light-years lacks the bright ring that surrounds most black holes. Discovered in 2011, astronomers explain its massive size may be because of a merger of two different black holes. 

Hercules A

The second last name in this list is the second most massive galaxy known to mankind. Hercules A is a supergiant elliptical galaxy near the Hercules constellation 2.1 billion light-years away from our planet with a diameter of 1500000 light-years, which was first discovered in 1714. This galaxy emits more power in radio wavelengths, billions of times more than the Sun. The 2 cosmic jets extending from the center of the galaxy can only be detected using radio signals, making it invisible to the human eyes. 

IC1101 

Last but definitely not the least, the largest galaxy found in our Universe till now is IC 1101, which is a supergiant elliptical galaxy with a diameter of 4000000 light-years that roughly estimates to be about 2000 times our Milky Way. Not only IC 1101 is the most massive galaxy ever, it also hosts one of the most massive black holes to ever exist, 40 to 100 billion larger than the Sun. The billions of stars in this galaxy are responsible for its golden yellow, which makes it one of the brightest galaxies as well. Founded in 1790, IC 1101 is 1.045 billion light-years far away from Earth.