In astronomy, the distance is so great that it does not make sense to use the usual notions. The numbers are huge, all visibility is simply lost. Therefore, astronomers have come up with other units. The smallest of them is 1 astronomical unit (and. E.). Got it, taking an average between the largest and smallest distance from the earth to the Sun, approximately 150 million kilometers.
The following unit is a light year isthe distance that a ray of light passes over the year. It is equal to 9.5 billion kilometers. For example, the distance to our nearest star - alpha in the constellation of Centaurus is equal to 4.3 light years.
But there is still a great unit - pareci. 1 parsec = 3.26 light years. But it was not enough. Recently used another kiloparsec: 1 KPS = 1000 Persikov. And megaparsec: 1 megaparsec = 1 million Persikov.
- The radius of our Galaxy is equal to 15-20 kiloparsecs.
- The distance that removed our Sun from the Galactic centre, is 10 kiloparsecs.
- The distance from the Earth to the closest neighbouring galaxies, the Large and Small Magellanic Clouds is approximately 38 and 36 kiloparsecs respectively.
- The nearest to us is the spiral galaxy of the Andromeda Nebula is about 300 kiloparsecs (more than a million light-years).
What is a light year?