Do we see the same stars from above and below the equator? (Beginner)

I am an Arizona cowboy. I was punchin cows, as I laid in my bedroll I wondered if the sky we look at is the same stars and such that the folks below the equator is. It drives me crazy.

No, the sky we see is not the same. At any point on earth at any given time, about 1/2 of the entire possible sky will be visible (basically, think of the sky above you as a giant "dome" which is equal to 1/2 of the entire sphere around the earth).

As the earth rotates, the part of the sky that you can see will change - unless you are exactly on the North or South Poles, in which case the sky will appear to rotate around a point directly above your head so you don't get to see any new stars as time goes on. Therefore, the sky that people on the North Pole see is completely different than the sky the people on the South Pole see. As you go down in latitude from the North Pole to the South Pole, the sky you can see will gradually change. So the sky that someone in Arizona sees has some overlap with the sky that someone in, say, Chile (in the Southern Hemisphere) sees, but it is not the same.

Taking this a bit further: for observers in Arizona and Chile, there is a region of sky that both can see as well as two regions that are exclusive for each observer. Stars above the North Pole will never be seen by the observer in Chile, as stars above the South Pole will never be seen by the observer in Arizona.

This page was last updated December 10, 2015.

About the Author

Dave Rothstein

Dave is a former graduate student and postdoctoral researcher at Cornell who used infrared and X-ray observations and theoretical computer models to study accreting black holes in our Galaxy. He also did most of the development for the former version of the site.

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