What are some interesting facts about the Milky Way?
1. The Milky Way is very old
At present, the scientific community believes that the age of the universe is about 13.7 billion years. However, scientists have also discovered that the Milky Way may be one of the earliest galaxies formed in the universe. This is based on the discovery of a 13.5-billion-year-old star in the galaxy (number J0815 + 4729) It is calculated that the star should also be one of the earliest formed stars in the universe. The heavy elements contained in the star through spectral analysis turned out to be only one millionth of the sun, indicating that this star was almost not in the universe when it was formed. Heavy elements.
2. The Milky Way is annexing small galaxies
Scientists have discovered that there are two smaller satellite galaxies on the edge of the Milky Way-the large and small Magellanic Clouds. There is reason to believe that many stars in these two galaxies are being attracted by the gravitational field of the Milky Way. Scientists believe that the size of the large and small Magellanic Clouds It used to be much larger than it is now, but due to the weak gravitational field of the galaxy, its own stars are constantly detached. Understanding the evolution of the large and small Magellanic Clouds can know the future changes of the Milky Way.
3. 200 billion stars are unobservable
In the universe, the Milky Way is only a medium-sized galaxy. Scientists have calculated that there may be 200 to 400 billion stars in the Milky Way, but humans can only observe about 250 billion stars at most. Most of the stars cannot be directly detected because of their orbits. Observed, but most of these stars are obtained by the Milky Way through the merger of other small galaxies, and the galaxies are also used to maintain enough material to produce stars.
4. The Milky Way is distorted
In the photos of the Milky Way we have seen, it is a plate-shaped spiral galaxy. Now, astronomical observations have found that the Milky Way is not a plane from the side, but a somewhat twisted shape at both ends. At the center of the galaxy, a large number of stars have formed. A highlight of the core area.
5. "Bubble" in the center of the galaxy
Scientists have only recently discovered that there are large structures called "Fermi bubbles" at both ends of the Milky Way, formed by the supermassive black hole "Sagittarius A *" in the center of the galaxy, extending up and down about 20,000 light-years. The reason for the formation of these eruptions is still unknown, but it must be related to the large amount of black hole engulfing material.
6. A galaxy merger is taking place in the Milky Way
Mergers between galaxies in the entire universe are very common. The Milky Way is also close to the nearby Andromeda galaxies. In the future, the two galaxies will collide and merge into a larger galaxy. The size of the Andromeda galaxies far exceeds the Milky Way. With one trillion stars, this process of galaxy fusion will continue for billions of years, and the galaxies after fusion will continue to move closer to other galaxies.
7. The position of the Milky Way in the universe
Although the size of galaxies is large enough for humans, the Milky Way is actually only one member of a large-scale galaxy cluster. There are thousands of galaxies around the Milky Way, including the fairy galaxies, to form a larger room. The female galaxy cluster, the entire Virgo galaxy cluster is moving at a speed of 1180 kilometers per second. It can be said that the Milky Way galaxy is not conspicuous in this huge galaxy cluster, and can only be regarded as one of the oldest members.
Understanding the Milky Way can see the operation mechanism of the entire universe. Although the distance between galaxies is far away from each other, they are constantly merging.
