AST101H5 Study Guide - Deferent And Epicycle, Semi-Major And Semi-Minor Axes, Orbital Period
Document Summary
Solar system was thought to be geocentric= everything revolves around the earth. Solar system is actually heliocentric= planets revolve around the sun. Age of solar system ~5 billion yrs. Light travels at fastest possible speed (300 000 km/s) Earth is rotating= spinning one spin takes 1 day (24hrs) Earth is revolving= orbiting 1yr. to orbit around sun. Constellations patterns of stars we see in the sky. Local sky the sky above the horizon where we are standing. Appearance of rising/setting sun earth spins towards the east. Cause of seasons earths spin is tilted by 23 degree to its orbital motion. This has 2 effects: sunlight"s concentration on the ground, # of hrs. of daylight. Moon orbits earth we track moons path in the sky using the background star patterns. Moons phases: also caused by moons orbit around earth moon doesn"t emit light it only reflects sunlight.
