ASTR 152 Lecture Notes - Lecture 1: Semi-Major And Semi-Minor Axes, Sidereal Time, Ecliptic
Document Summary
Celestial sphere : imaginary sphere upon which planets and stars travels. Diurnal motions : celestial motion due to earth"s rotation. Mean solar day : time it takes the earth to get back to its original position. Cosmology: the study of the universe in the past, present and future turned from religion towards science. Aristotle: made only observations to generalized the things he see. earth at the center (geocentric) Hipparchus: came up with ideas. he came up with the stellar parallax. shifting off the stars in the background due to earth"s motion. the result of this stellar parallax was just too small. Ptolemy: made an elaborate model, and wrote a 13 volume work on astronomy. Kepler: he was a mathematician. he created a model for planetary orbits geometric forms with sun at a centric. P - sidereal periods of a planet in years.