Astronomy 2021A/B Chapter Notes - Chapter 2: Milky Way, Terrestrial Planet, Big Bang
27 Sep 2017
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Document Summary
Milky way galaxy: huge, disk shaped collection of stars. Galaxy: a great island of stars in space, containing from a few hundred million to a trillion more stars. Our solar system is located about halfway out through the disk of the galaxy, where it orbits the galactic center once every 230 million years. Galaxy clusters: groups of galaxies with more than a few dozen large members. Superclusters: the regions in which galaxies and galaxy clusters are most tightly packed. Universe: the sum total of all matter and energy, encompassing the superclusters and voids. 1 light year is the distance that light can travel in 1 year (about 10 trillion kilometres) Alpha centauri: the nearest star system to our own; 4. 4 light years away. Just as planets orbit the sun, the stars orbit the center of the milky way galaxy. The more massive the galaxy, the stronger its gravity and the faster stars should be orbiting.
