AST101H1 Chapter Notes - Chapter 1: Galactic Center, Orion Nebula, Astronomical Unit
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AST101H1 Full Course Notes
Chapter 1 - a modern view of the universe. Earth = planet that orbits an average star (sun) in a vast universe. Pic. on page 1 displays a galaxy filled with billions of stars; this photo can tell a lot about our place on the universe Earth = planet in our solar system, which consists of the sun (a star), the planets and their moons, and countless small objects that include rocky asteroids and icy comets. Our solar system belongs to the huge, disc-shaped collection of stars called the milky. A galaxy is a great island of stars in space, containing b/t a few hundred million and a trillion or more stars. Milky way is a large galaxy containing more than 100 billion stars. Our solar system is located a little over halfway from the galactic center to the edge of the galactic disk. Billions of galaxies scattered in space, some are isolated but many are found in groups.