ASTR 101- Final Exam Guide - Comprehensive Notes for the exam ( 35 pages long!)
1 Dec 2017
School
Course
Professor
Document Summary
The cosmic calendar: a scale on which we compress the history of the universe into 1 year. The matter in our bodies came from the big bang, which produced hydrogen and helium. All other elements were constructed from h and he in stars and then recycled into new star systems, including our solar systems. On a cosmic calendar that compresses the age of the universe into 1 year, human civilization is just a few seconds old, and a human lifetime is a fraction of a second. Contrary to our perception, we are not sitting still". We are moving with earth in several ways, and at surprisingly fast speeds. The earth rotates around its axis once every 24 hours. Earth orbits the sun (revolves) once every year. At an average distance of 1 au = 150 million kilometres. With earth"s axis tilted by 23. 5 (pointing to polaris) It rotates in the same direction it orbits, counterclockwise as viewed from above the.
