AST 2003 Study Guide - Quiz Guide: Lunar Eclipse, Spiral Galaxy, Perseus Arm
Document Summary
Test 1 review: an astronomical unit is the distance between the sun and earth. It is 9. 2956 x 10^7 mi (1. 4960 x 10^11 m) or 93 million miles: a light year is the distanced travelled by light in one year at the speed of light. One light year is about 6 trillion miles: one parsec is 3. 26 light years. Universe (earth, milky way, local group, supercluster) [end of test: earth. Earth is on the cygnus arm that is under the sagittarius are and above the orion arm. Earth spins on an axis that is tilted 23. 5 degrees, this tilt causes us to have seasons. We have a magnetic field that is generated in a circular motion through our poles that comes from our liquid core(lava). This field keeps the moon in our orbit. The earth is about 4. 5 billion years" old.
