The solar system is located between the two main arms of our galaxy.
Our galaxy, called the Milky Way, is a huge collection of stars and other astronomical objects that we actually cannot see in its entirety. Because we are located inside this galaxy, and therefore scientists judge the appearance of the Milky Way by other similar objects. Nevertheless, astronomers know enough about the structure of our galaxy to say exactly in which region the Earth and the entire solar system are located, writes EarthSky.
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Our galaxy is a barred spiral galaxy with two main spiral arms extending from the center. If you imagine the Milky Way as a disk, then the Sun and the entire solar system are approximately halfway from the center of the galaxy to its visible edge. The Earth and the Solar System are located between the Perseus spiral arm and the Centauri spiral arm. But more precisely, we are on the edge of a relatively small spiral arm called the Orion Arm.
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Our location in the galaxy is thought to be important because it turns out that, just like around stars, galaxies have their own habitable zones. That is, places where life is more likely to exist.
Model of the appearance of the Milky Way. The yellow dot indicates the position of the Sun
Photo: Wikipedia
Around 95% of the stars in our galaxy cannot have habitable planets. The fact is that many of these stars revolve around the center of the galaxy in orbits that take them through deadly spiral arms.
Any star system passing through such regions is exposed to lethal radiation from the vast number of stars in these arms. Our Solar System rotates quite far from the center of the galaxy, and is located in a relatively quiet and calm space between the spiral arms.
This Hubble Space Telescope image shows galaxy UGC 12158. It is a barred spiral galaxy that scientists believe is very similar to the Milky Way.
Photo: NASA
Scientists are still continuing to study the Milky Way, because there is still much we do not know about our galaxy. It is believed that the Milky Way has a diameter of 100 thousand light years and contains from 100 to 400 billion stars. It was previously thought that our galaxy has 4 main spiral arms, but now astronomers say there are only two. The remaining spiral arms, and there are many of them, are secondary in the Milky Way and have different sizes.
The Sun, Earth and the rest of the planets in the solar system are located on the edge of such a secondary arm called the Orion arm. We are believed to be 26 thousand light years from the center of the Milky Way.
Model of the Milky Way. It is believed that the Milky Way has a diameter of 100 thousand light years and contains from 100 to 400 billion stars. It was previously thought that our galaxy has 4 main spiral arms, but now astronomers say there are only two. The remaining spiral arms, and there are many of them, are secondary in the Milky Way and have different sizes
Photo: NASA/JPL
As for the Orion Arm, astronomers say it is approximately 3,500 light-years thick and over 20,000 light-years long. Although it was previously believed that the length of this arm is no more than 10 thousand light years.
The Orion Arm gets its name from the constellation Orion, which is one of the brightest constellations in winter in the northern hemisphere and summer in the southern hemisphere of Earth. Some of the brightest stars and most famous celestial objects in this constellation, such as the star Betelgeuse, the stars of Orion’s belt and the Orion Nebula, are neighbors of the Sun.
The reason we see so many bright objects in the Orion constellation is because when we look at it, we are looking at our own local spiral arm.
As I already wrote focus, A catastrophe is expected in the center of the Milky Way, because a huge space object is flying there. According to scientists, this object is doomed to disappear in the inhospitable center of our galaxy.
