I was wondering about how much of the night sky one could see from various locations on the Earth. At any one time, near sea level, how much is visible? My guess is that much less than half is visible, with the rest being blocked from view by the earth. Is that correct? How small a portion are we viewing when we look up? And over the course of a year, it seems that different parts of the Earth would see a larger or smaller proportion of the whole. For example, if one were at the north pole, one would see nearly the same portion of the sky every night for half a year, and see nothing the other half due to the sun. If one were on the equator instead, one would see huge new vistas as the Earth traveled around the Sun, depending on the time of year. So how small is this "at any one time" portion, and do people at the equator see pretty much everything over the course of a year, or is a significant portion still invisible, even to them? Do people at the equator ever see the North Star?