How long does the solar system revolve around the center of the Milky Way?
News from September 2nd, Beijing time, according to foreign media reports, we have long been used to distinguishing the four seasons of the year by the position of the earth relative to the sun. However, although the earth’s journey around the sun is very important for humans on earth, it is really insignificant compared to the epic journey of the sun-and our entire solar system-orbiting the center of the galaxy.
It takes about 220 to 230 million earth years for the sun to revolve around the Milky Way in its orbit. In other words, if we use the galactic “clock” to measure time, our earth has only existed for about 16 years (in galactic or cosmic years). As a unit), the formation of the sun is only 20 years old, and even the entire universe has existed for about 60 years.
The process of the solar system revolving around the Milky Way is very similar to the process of the earth revolving around the sun. It’s just that the solar system does not revolve around a certain star, but revolves around a super-mass black hole located in the center of the Milky Way, and this super-mass black hole has a huge gravitational attraction to all matter in the Milky Way.
The sun’s revolution speed is very fast-reaching about 230 kilometers per second, which is equivalent to 500,000 miles per hour (about 804,000 kilometers) . The sun keeps revolving around the center of the Milky Way, so it will not be drawn to the black hole.
Our place in the galaxy
Compared with the earth year, the galactic year represents a larger unit of time. But in the Milky Way, this time unit is not uniform. The Milky Way that we people on Earth call is relative to the position of the Earth in the Milky Way. We can say that a galactic year is about 220 million or 230 million earth years, but on other planets in the galaxy, their galactic years are different.
The diameter of the Milky Way is about 100,000 light years, and our Earth is 28,000 light years away from the center of the Milky Way. If you think of the Milky Way as a city, then our earth is probably located in the suburbs. If it is a star whose orbit is close to the black hole in the “city center”, then a galactic year is relatively short, but in the “suburb”, that is, our solar system At the location, the Milky Way is a little bit longer.
Similar rules apply to different planetary year lengths. For example, Mercury is the innermost planet in the solar system. Mercury revolves around the sun in only 88 earth days. Uranus, the seventh planet in the solar system, orbits the sun in 84 earth years. The orbital period of the distant dwarf planet Pluto is 248 earth years.
Although the physical mechanism of planetary orbits is similar to the mechanism that shapes the orbit of the solar system around the Milky Way, there is still a question worth mentioning: How do astronomers calculate the length of the Milky Way? In fact, this is a fairly basic science, already very clear in the early development of modern astronomy.
It is mainly to observe the movement of stars around the Milky Way. You can observe the movement of stars around the Milky Way, and then deduce the length of the Milky Way from the movement speed and direction of other stars.
If you think this post can be helpful to somebody else, please share it on Twitter, Facebook or Whatsapp it to friends. There are buttons below for this (easy to use too)! Join Over 5,000 + Readers. Get a free daily update via Email HERE