What is the Milky Way?

The Milky Way or Milky Way is the celestial system where the solar system is located, including120 billion stars, a large number of star clusters and nebulae, and various types of interstellar gas and interstellar dust.

Its diameter is about 100000 light years, its center thickness is about 12000 light years, and its total mass is140 billion times that of the sun. The Milky Way is a spiral galaxy with a spiral structure, that is, it has a silver center and four spiral arms, which are 4500 light years apart.

The projection of the Milky Way in the sky is like a shining river flowing in the sky, so it was called the Milky Way or Tianhe in ancient times. You can see the Milky Way all year round, but at the turn of summer and autumn, you can see the brightest and most spectacular part of the Milky Way.

The main constellations that the Milky Way galaxy passes through are Cygnus, Eagle, Fox, Sagittarius, Ophiuchus, Shield, Sagittarius, Scorpio, Aquarius, Rectangular, Wolf, Triangular, Compass, Fly, Southern Cross, Vela, Tail, Unicorn, Orion and Taurus.

The Milky Way is a rod spiral galaxy system, which consists of 1 0,000 to 400 billion stars, thousands of clusters and nebulae. It looks like a big disk, the center of the side is slightly protruding, and the top looks like a whirlpool. Four spiral arms extend evenly and symmetrically from the center of the Milky Way. Its diameter is about 100000 light years, its center is about 10000 light years, and its edge is about 3000-6000 light years. This center is called the Silver Heart, and both it and the spiral arm are densely populated with stars, so it looks like a vast expanse of white at night.

The sun is located on an arm called Orion arm, about 26,400 light years away from the center of the Milky Way, and rotates counterclockwise (it takes about 250 million years for the sun to rotate around the center of the Milky Way).