In the second volume of the sixth grade, how does science use star maps to correspond to time?

In the second book of grade six, science can observe the positions of stars and planets, and use the sun parallax of stars to correspond time with sundials and star timers, as follows:

1. Observe the positions of stars and planets: The positions and movements of stars and planets in the night sky are regular. By observing their positions and changes, we can roughly determine the time and season. For example, in spring, there will be spring constellations in the sky, such as Orion and Cowherd. By observing their positions and changes, the time can be determined.

2. Use the solar parallax of the star: the solar parallax refers to the position difference of the observer on the star in two adjacent days on the earth. Every day, different constellations rise and fall in the sky, and parallax can help us determine the rise and fall time of these constellations. For example, if you observe the same star twice and find that it was in a specific constellation at the first observation, but it has moved to another constellation at the second observation, then you can calculate the time by observing this change.

3. Use sundials and astronomical clocks: sundials and astronomical clocks are instruments that use the positions of the sun and stars to measure time. A sundial measures time by the position of the sun, while an astronomical clock measures time by the position of a constant star. On the star map, you can find specific constellations, and then determine the time according to their positions and movements.