The Observable Universe has 2 Trillion Galaxies – 20 Times More Than Previously Thought
As most of us know, our Solar System is located somewhere midway between the Milky Way Galaxy’s core and edge. Moreover, the galaxy itself is some 100,000 light years in diameter which in alone can give us a rough estimate of how many stars there actually are within it. Of course, nobody has actually counted them all, and probably never will, but the way people went about it was to get a rough estimate. In any case, depending on what the average sized star is considered to be, there are somewhere between 100 to 400 billion stars in our own galaxy, probably even more. With that being said, why we haven’t already taken advantage of all that prime real estate, is anyone’s guess.
Furthermore, our own Milky Way galaxy is but a very small and insignificant tip of the overall cosmic iceberg, because there are countless other galaxies out there. According to a recent study in the matter, it turns out that in the observable universe, there are roughly 2 trillion other galaxies, just waiting for us to discover them.
“It boggles the mind that over 90% of the galaxies in the universe have yet to be studied,” commented Christopher Conselice of the University of Nottingham, who led this study.
In 1924, astronomer Ewin Hubble realized that a small part of the universe where he was looking at was not in fact part of our own galaxy, but rather another one completely. This was the Andromeda Galaxy, the closest to our own and the largest in our local cluster of galaxies. Ever since that discovery, astronomers have come to the conclusion that there are countless others out there. But how many there actually are, and just like the stars within our own Milky Way, is something no man can ever count on his own.
This is why they made use of something which is a fairly new invention, namely computer models. The way they went about it was to input every photo the Hubble telescope has ever taken of “infinity” over the past 20 years and converted them into 3D. This process took a very long time and it even required the development of new numerical models. But in the end, they did manage to come up with a rough estimate of what could possibly be out there. And that number comes around to 2 trillion galaxies. Keeping in mind that most have on average the same number of stars as our own, it again begs the question of why do we still fight over the same speck of cosmic dust, and not take advantage of the utter infinity of resources and possibilities out there.
In any case, these researchers also came to the conclusion that the number of galaxies has dropped significantly since the birth of the universe since galaxies have a tendency of merging together due to their own gravitational pull they have on each other. For instance, it is estimated that in some 4 billion years, the two largest galaxies in our own local cluster, the Andromeda and Milky Way galaxies will collide to form an even larger one.
“These results are powerful evidence that a significant galaxy evolution has taken place throughout the universe’s history, which dramatically reduced the number of galaxies through mergers between them – thus reducing their total number. This gives us a verification of the so-called top-down formation of structure in the universe,” explained Conselice.
The reason for why the estimated number was smaller, was because many galaxies out there simply weren’t bright enough for our telescopes to see them.
“Who knows what interesting properties we will find when we observe these galaxies with the next generation of telescopes?” he asks.