understandable.

Regardless, the stars do appear to move, and in an orderly way. For instance, simplifying things significantly is the fact that the stars all seem to move together, as one unit, as if they were attached to a solid, moving background. They are not. Still, that is what it looks like.

The stars form the canvas on which any astronomical spectacle plays out. Stars are so distant that they physically move imperceptibly to the naked eye, within the span of human history. The much closer planets, satellites, and minor bodies of the solar system, on the other hand, change their relative locations as they and the earth move about the sun. Thus, the stars, which appear fixed, serve as a ready reference for specifying the ad dress of anotherdiurnal path lies in the vicinity of the horizon, before sunrise and after sunset, longer than does the winter sun's. What is the difference between the sun's behavior at these two different times of year? From the point of view of temperate dwellers the sun must cross from one celestial hemisphere to the other in the summer. Not so in the winter. The result is that, in the summer, the sun spends more time just below the horizon and produces longer dusks and dawns than it does in the winter. In chapter 7, we will see why long twilights are absent altogether near the earth's equator, but standard fare close to the poles.

If your astronomical horizon differs greatly from the real horizon, your dusk and dawn experiences may