Why can you see the sky from the north pole to the equator when you can only see a few miles of water to the horizon and you can't see airplane tracks that far away - I do not understand this?

Answer 1

What, exactly, did you see? - You can basically see anything for which you have line-of-sight, that is, if a straight line between the object and you doesn't go below the horizon.

I think the questioner may be mixing up the "celestial equator" and the Earth's equator.

The celestial equator is the "projection" of the Earth's equator onto the sky. It a great distance away, effectively at infinity.

Let's consider the difference between the two equators.

Normally, you can see only a few miles to the horizon, depending on your height above your surroundings. Obviously you can't see the Earth's

equator from the North Pole.

Things above ground such as airplane tracks can be seen when they are further away than the horizon, but still your visibility is limited by the Earth's surface.

However, from the North Pole, you can see as far south in the sky as the

celestial equator.

So, you could just about see a star in that part of the sky. The stars are light years away, of course.

Imagine you are near a distant star on the celestial equator. In theory, at that distance, you could see one full hemisphere of the Earth from pole to pole.

So, someone at the Earth's North Pole could see that star.

To sum up: it's because the stars are so far away that you can see a star

on the celestial equator from the North Pole.