Our planet is also changing position. In six months, the Earth will go from one side of the sun to the other. This is a change in distance of almost 300 million kilometers, and is enough to cause a noticeable change in position for some of the nearest stars. In fact, parallax is an important tool for measuring the distance to these stars. (Here are other ways to measure stellar distances.)
So yes, the constellations change, but not so much.
Find your length
Here’s how to find your length with a clock and a star chart. Let’s start with the star chart. Suppose there is a star in this graph that will always be directly above a point in Greenwich, England, at 4 a.m. local time, which we would call Greenwich Mean Time. (I didn’t choose Greenwich at random. The main meridian, or 0-degree longitude line, crosses the Royal Observatory Greenwich, so it’s good for measurements.)
Now imagine that you are somewhere else and trying to figure out where you are with the same star. You need to know what time it is when this star appears directly above it yours location. Hence the clock.
Checking the time reveals that where you are, this star appears directly at 1 a.m., instead of 4 a.m., three hours before Greenwich. That means you’re three hours a day west of Geenwich. If you want to convert it to degrees, it would be (3/24) × 360 = 45 degrees. This would put you on a long line across Greenland and Brazil. (Things can get a little more complicated than that, as you probably wouldn’t have a star directly above you, but you get the idea.)
Then, if you’re in the northern hemisphere, you can use the North Star to calculate your latitude and determine your exact location on the planet, which is where these latitude and longitude lines intersect. Hopefully, it’s not in the middle of the Atlantic Ocean.
What’s wrong with Knight of the Moon?
Now it’s time to talk about it Knight of the Moon. (Some spoiler in advance.) In episode 3, Moon Knight, Khonshu’s earthly avatar, reunites with Marc’s wife, Layla. They are trying to find the tomb of the Egyptian god Ammit. If Ammit is released, he will do bad things to the human race, so they really want to get there first. They gathered parts of a funerary shroud to form an ancient star chart and want to use it to find the location of the tomb, which is like celestial navigation.
But there is a problem: this map was made 2,000 years ago, so the arrangement of the constellations is incorrect. Since then, the stars have moved to new positions. Because Moon Knight is Khonshu’s avatar, he uses his powers to move the stars in the sky back to the pattern shown when the map was created. Problem solved. Moon Knight and Layla can reach Ammit’s grave.