It's hard to believe, but scientists only discovered the existence of galaxies in the 1920s. Astronomers from all over the world had been observing the Andromeda Nebula for years, but were sure that it was part of our Milky Way galaxy. The American astronomer Edwin Hubble, after whom the legendary space telescope is named, was the first to discover that this nebula was a separate galaxy. While observing the stars in Andromeda, he was able to calculate the distance to the nebula and was surprised to find that it was much further away than previously thought. The discovery that Andromeda is a separate galaxy began a new era in cosmology and astronomy. Scientists are still studying Andromeda and recently estimated the probability of its collision with the Milky Way galaxy.
Andromeda and the Milky Way are moving toward each other and could soon merge. Image source: iflscience.com
How Many Galaxies Are There in the Universe
More than 100 years have passed since the discovery of the Andromeda Galaxy. During this time, astronomical equipment has become many times more powerful and scientists have discovered many other galaxies. For example, we know about the existence of the Large Magellanic Cloud, which is located at a distance of 160 thousand light years and contains about 30 billion stars. Also not far from the Milky Way is the Small Magellanic Cloud – we are separated by 200 thousand light years, it contains about 3 billion stars.
Large and small Magellanic clouds. Image source: lenta.ru
The total number of galaxies in the Universe cannot be counted. Scientists only assume that their number may be about 2 trillion pieces.
Read also: What does the Milky Way galaxy revolve around?
The closest galaxy to us
The solar system is located in the Milky Way galaxy. Of all the trillions of galaxies, Andromeda is the closest to us. It has a spiral shape and contains about 1 trillion stars. But this is an approximate number, because it is located in a half-turn relative to the Earth and some stars of the Milky Way block the view. It is 2.5 million light years away from us and is twice the size of our galaxy.
The Andromeda Galaxy has a spiral shape. Image source: mentoday.ru
Thanks to powerful telescopes, we know that the Andromeda galaxy is moving at about 402,336 kilometers per hour. It is believed that in about 4.5 billion years, it will collide with our Milky Way galaxy and they will become one. The new galaxy will be circular in shape and will consist of an unimaginable number of stars scattered in new orbits. If the Earth, the Sun, and other objects we know survive this catastrophe, they will acquire new coordinates in space.
You will be interested in: 10 interesting facts about the Andromeda galaxy
When Andromeda and the Milky Way will collide
Scientists have recently estimated the probability of the merger of the Andromeda and Milky Way galaxies. To do this, they studied fresh data collected by the Gaia and Hubble space telescopes. According to the authors of the new scientific work, in order to predict the mergers of galaxies, it is necessary to know not only the speed and direction of their movement. In addition to all this, it is important to take into account the dynamic friction between galaxies, which can cause a loss of kinetic energy.
The researchers also took into account the influence of other galaxies on Andromeda and the Milky Way. They concluded that given the latest scientific evidence, the likelihood of them colliding is much lower. Their calculations showed that in the next 10 billion years the collision of the Milky Way with Andromeda will not occur with a probability of 50%.
Collision with the Milky Way on video
In fairness, it should be noted that the researchers gave a very convenient answer for themselves. Having announced that the galaxies will collide with a 50% probability, they seemed to say that they “either collide or not.” Be that as it may, scientists are now slightly doubting the future catastrophe. If earlier we were all sure that in the future our galaxy would look completely different, now there is reason to think that everything will remain as before.
In general, in addition to stars, planets and asteroids, scientists also carefully study galaxies. Discoveries in this area are made often, so to not miss anything, subscribe to our Zen channel.
Considering that the number of galaxies is in the trillions, the Universe has a size that we cannot even imagine. Have you ever wondered what is in the space between galaxies? You will find the answer to this question in this material.