In people's eyes, the position is similar, but every planet has an orbit, and the position of the Big Dipper cannot be constant in the north.
Because the earth revolves around the sun, the tilt direction of the earth's axis also changes, but the distance between the Big Dipper and the earth is greater than the radius of the earth's revolution, so the change of the earth's axis caused by the earth's revolution can be ignored.
Extended data:
The Big Dipper appears in different directions in the sky at different seasons and different times at night, so the ancients decided the seasons according to the direction pointed by bucket handle at the beginning of fainting: bucket handle points to the east, and the world is spring; Guide to barrel handle, it's summer in the world; Bucket handle refers to the west, and the world is autumn; The barrel handle refers to the north, and it is winter all over the world.
The Big Dipper is also called "Beidou" for short. Not far from the north celestial pole, seven bright stars are arranged in a barrel shape (see photo). All six stars are second-class except delta, which is a third-class star.
Polaris can be found by connecting the first two stars of the Big Dipper and extending it to the mouth of the Big Dipper for about five times, which is usually used as a sign to indicate the direction and identify the constellation.
In addition, according to the bucket handle curve of the Big Dipper, after drawing an arc, you will meet arcturus, which is one of the 2 1 bright stars, that is, the alpha star of the constellation Capricorn.
References:
Big Dipper-Baidu Encyclopedia