AST101H1 Chapter Notes - Chapter 1: Milky Way, Virgo Supercluster, Astronomical Unit
29 Jan 2016
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AST101H1 Full Course Notes
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State the full cosmic address of earth. Correctly use the terms planet, dwarf planet, moon, star, solar system, and galaxy. State the approximate sizes: planets, stars, solar systems, and galaxies, in au and ly. Astronomical unit (au): earth"s average distance from the sun (150 million km) Light year (ly): distance light can travel in 1 year ( 10 trillion km: light takes time to travel through space: Everything you see into space is how it looks like back in time. The universe up to 14 billion light-years ago (since earth existed) The portion of the entire universe that we can potentially observe. [1] the big bang theory: universe is exponentially expanding implies galaxies were closer in the past. [2] stellar lives and galactic recycling: early universe contained only hydrogen and helium, other elements were made by stars and recycled from one stellar generation to the next.
