How does tracking direction through stars work?

66 views
0

Ok, so I just learned how using a star to track direction is supposed to work. Basically you set up two sticks one smaller than the one in front, and use them to line your vision up with a star. The rule is, if the star moves up, you’re facing east. If the star moves down, you’re facing west. If the star moves left, you’re facing north. If the star moves right, you’re facing south.

What’s got me confused is how does a star moving left indicate you’re facing north? On a compass east is 90 degrees to the right of north, so if you’re facing north, shouldn’t it look like the star is moving to the right?

In: 2

Remember, **the star isn’t moving**. You are moving, because the Earth rotates. So, if the star appears to move left that’s because you and your sticks have moved right.

Well, the stars themselves aren’t moving, but the earth *is* rotating. So as you trace how the stars “move” across the sky, you will see that they travel from *east* to *west*. Has nothing to do with compasses specifically, because those work based on magnetic fields on earth, not the motion of the stars.

All stars move in the same direction, including the sun. That means that all stars rise in the east and set in the west

If you’re in the northern hemisphere and do a long exposure centered on Polaris (the north star) you’ll see that all stars seem to rotate counter clockwise around that one point (the axis of Earth’s rotation)

So if you face east you’ll see stars rising, then you face North and they move from your right(east) to your left (west), then they set in the west