Things you don't know about galaxies

For about 4 billion years, the Milky Way galaxy will merge with the Andromeda galaxy. The result of the integration process will be an elliptical galaxy called "Milkomeda".

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1. The 18th-century philosopher, Immanuel Kant, was one of the first to theorize that the Milky Way (our Milky Way or Galaxy) is not the only galaxy in the universe. . He coined the term 'island universe' to describe a galaxy.

2. Astronomers estimate that about 100 billion galaxies in the universe can be observed.

3. The English term Milky Way was earliest used in Geoffrey Chaucer's "The House of Fame" poem in the 14th century.

4. As the universe expands, all other galaxies are backing away from our Galaxy. Further galaxies from the Milky Way galaxy are moving faster than nearby galaxies.

5. Some galaxies are far away from the Milky Way, an elliptical shape, like a rugby ball, or flat and flat disk shape with the Milky Way-like arms. The galaxy also has an irregular shape, which includes many dwarf galaxies. The smallest galaxies in the universe contain only a few hundred to a few thousand stars (compared to 100 billion stars in the Milky Way galaxy).

6. We will often find dwarf galaxies around larger galaxies. Dwarf galaxies are often lost to stars by larger neighboring galaxies through gravity. Stars in the sky are part of the dwarf galaxies ripped apart. We can't see it with the naked eye.

7. We also can't see the giant black hole hidden in the center of the Milky Way galaxy, although looking in the right direction from the constellation Sagittarius. Most galaxies have a black hole in the center, and astronomers have calculated its consistent mass about 1/1000 of the mass of the parent galaxy.

8. Two of the galaxies closest to the Milky Way are the Small Magellanic Cloud and the Large Magellanic Cloud, which may not have black holes, or because they both have low masses so their black holes are too small, difficult to play show.

9. Each galaxy contains dust in the interstellar space, dust makes light look redder than itself when visually observed, which can make it difficult for astronomers to study the characteristics of the stars. star.

10. The Milky Way turns at a speed of 250km / s and completes a round of 200 million years. Galaxies are spinning faster than predicted based on stars' gravitational pull. Astronomers deduce that additional gravity comes from dark matter, a material that does not emit or reflect light.

11. Most of the space in the galaxy is empty, if the stars in the galaxy are orange, they will be 4,800km apart.

12. If galaxies are about the size of an apple, the distance between nearby galaxies is only a few meters. Relatively close galaxies are sometimes unified galaxies.

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