How do you know a year has passed using a constellation?

Answer 1

Well, you could spot one star in a constellation ... one that you can easily find

and recognize again. Then line it up with a tree or a corner of the roof of your

house, jab a stick in the ground where you're standing, and look at the time on

your watch.

The next time that star is in the same place, at the same time by the clock,

while you stand in the same place, will be a year from tonight.

(Tomorrow night, it'll get there 4 minutes too early.)

Answer 2

One way to know a year has passed using a constellation is to observe its position in the night sky at the same time each night. Over the course of a year, the constellation will appear to shift slightly due to the Earth's orbit around the Sun. By tracking these changes, you can infer when a year has elapsed.