It’s no secret that everything in our universe moves, including the stars, while their movements relative to each other are chaotic and the stars that we see in the sky at night are no exception. During the lifetime of an average person (70-80 years), changes in the position of the star will be little noticeable, because despite the fact that the stars have a rather high speed (about 50 km / s), our eye at such a distance cannot keep track of the change in the position of the star. An exception is only a couple of stars with anomalously high speeds, whose motion across the sky becomes noticeable over several years of observation.
Although we see the stars of any constellation as in the same plane, in fact they are at different and very large distances from the Earth, and their relatively equal brightness is explained by the fact that more distant stars turned out to be brighter than those that are closer.
Changing the position of stars that are closer to us will be more noticeable. This effect can be easily explained: let’s say we are in the place marked with a blue dot in the figure above and see a person at a distance of 50 meters. He travels 100 meters as shown in the picture. Now let’s take an airplane at a distance of 1 km, so that it visually hits the same point as a person, the airplane must fly 2 km. In this case, the angle that the person and the plane describe will be equal.
Similarly, the distance from the star Vega from the constellation Lyra to our Sun is 25 sv. years, while all the other stars of this constellation are at a distance of about 600-800 sv. years, therefore, after a significant period of time, the change in the position of Vega will be more noticeable than that of other stars and the constellation will be deformed.
The image below shows how the known constellations have changed from 50,000 BC to the present day, and how they will change in the next 100,000 years.
The rest of the constellations will be deformed in the same way. It is unlikely that one person will be able to observe this process, because the stars will shift quite noticeably over several centuries, but by transmitting the data of our observations to descendants, we can provide them with the opportunity to compare their constellations with those that we saw. In the end, in a couple of million years the sky will change beyond recognition, and those who will live will then unite the stars into completely different constellations.
Author: Vladislav Kigim. Edited by Fedor Karasenko.
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