The galaxy is a congestion of stars, dust, a huge system which is connected by gravitational forces. "Галактикос" in translation from Greek means "dairy". However, there is also just visual explanation for such name, it is possible just to peer into the night sky at a clear weather and to see a wide white strip as if the trace from the spilled milk is and there is a Galaxy, the Milky Way.
Instruction
1. However, the Milky Way is only our Galaxy, them there is a lot of all. At distance about 150000 light years the next to us is located the Galaxy "Magellanic clouds". Each galaxy contains hundreds of billions of various stars, and all of them rotate around a uniform galactic kernel – a certain congestion in the center of the galaxy. All stars in the galaxy are connected among themselves by gravitational forces.
2. Scientists distinguish three classes of galaxies today: wrong, spiral and elliptic galaxies. Galaxies I can exist in the Universe groups, in couples, and our galaxy is included into such group – the local group of galaxies numbering about 30 associations. The small group to space measures is included into so-called Sverkhskopleny Maidens. It is possible to tell that stars are grouped to galaxies, like the people settling in the cities, and galaxies create the associations – such "regions" of the Universe.
3. From remote distance all galaxies look quite peacefully, but an impression this deceptive. Actually the galaxy represents a peculiar military arena. Periodically in galaxies there are explosions and gas releases that is similar to eruptions of volcanoes on Earth. Sometimes there are collisions of galaxies among themselves therefore it is impossible to call existence of these space objects completely peace and silent.
4. After collision two galaxies can unite, forming one, larger connection, than was before. It is interesting that distances to galaxies are estimated in millions of light years that means that we see galaxies not such what they are time at the moment – we see them in the past, at the age of several million years ago. Scientists can say today that with age galaxies become shallow – the galaxy, smaller by the sizes, the it is more senior. To receive the large galaxy similar to our association, merge of 10-100 small galaxies is required.