AST 1001 Study Guide - Midterm Guide: Angular Distance, Eclipse Season, Angular Diameter
Document Summary
Our place in the universe superclusters, galaxy clusters, local group, milky way galaxy, solar system, earththe speed of light. The average distance between galaxies is expanding over time. This implies that they may have been closer together. Scientists used the observed expansion rate to calculate that the big bang (the point at which expansion began) occurred 14 bill yrs agoscaled version of the solar system and galaxy 1/10th billion of actual size. Lots of empty spacemotions within the galaxy our solar system completes one orbit around the galaxy every 230 million years at a speed of 800,000 kilometers per hour. We only see half of the celestial sphere, while the ground blocks the other half. angular size and angular distance our lack of depth perception makes it difficult to judge true sizes or separation of objects in the sky. The angular size of an object is the angle it appears to span in your field of view.
