ASTR 3 Study Guide - Final Guide: Circumpolar Star, Virgo Supercluster, Observable Universe
Document Summary
Esentially produced only two chemical elements: h & he, the rest have been. Sun is one of more than 100 billion stars in the milky way. Our galaxy is one of about 40 galaxies in the local group. Local group= one small part of the local supercluster. When we look billions of light-years away, we see pieces of the universe as they were billions of years ago. The age of the universe limits the extent of our observable universe. The distances between planets are huge compared to their sizes. The observable universe contains roughly 100 billion galaxies. Our lifetime compared to the age of the universe lasts only a fraction of a second. Earth rotates on its axis once each day and orbits the sun once each year. We move randomly relative to other stars in our local solar neighborhood. Stars are so far away, their motion is undetectable by the naked eye.
