PHYS 384 Chapter Notes -The Moons, Simple Explanation, Apparent Retrograde Motion
Document Summary
Section summary: stars and other celestial objects appear to lie on a great celestial sphere surrounding. We divide the celestial sphere into constellations with well-defined borders. Cultures called patterns in sky constellations: constellation = region of sky with well defined borders. 88 official: every point of sky belongs to a constellation, star charts help find them, celestial sphere = imaginary sphere on which all objects in the sky appear to reside when observed from earth. Illusion due to lack of depth perception b/c stars are so far away. Stars in constellation seem close but are at very different distances from earth. All stars seem to lie on celestial sphere. Earth seems to be at center b/c its where we are when looking in space. Useful illusion -> allows to map the sky as we see it. North celestial pole -> above north pole. South celestial pole -> above south pole.
