Astronomy Review Questions1. What is our place in the universe?Earth is located in our Solar System which is located in the Milky Way galaxy. A galaxy is a collection of stars. The Milky Way is in a collection called the Local Group. This makes up our universe. 2. How big is the universe?PRETTY DAMN BIG.3. What is a planet? Planets are defined by their size, physical characteristics but also by:- Whether or not it orbits a star- Is massive enough for its own gravity- And dominates its orbital region4. What causes seasons?Seasons are caused by the tilt of Earth’s axis which in turn causes the Sun’s path through our sky and theintensity of sunlight to vary over the course of the year. The orientation of the axis relative to the Sun changes over the course of the orbit. 5. Why do the constellations we see depend on the time of the year?The Sun’s apparent position among the constellations change as the Earth orbits the Sun, and therefor, we see different constellations year round.6. Why do we see phases of the moon?Half of the moon always faces the sun, as a result, as it orbits the Earth, a combination of faces are visible. 7. What causes eclipses?When the Moon and Earth both cast shadows in sunlight.8. Why did the ancient Greeks reject the real explanation for planetary motion?They believed in an Earth-centered universe and came up with a complex explanation for retrograde motion. Because of their inability to detect stellar parallax, the ancient Greeks had no proof.9. How did the Greeks explain planetary motion? Geocentric model – didn’t explain retrograde motion of planets, violated idea of “heavenly perfection”. Ptolemaic model – each planet moves on its own circular plane around the Earth.10. What does the solar system look like? The Sun, terrestrial planets, Asteroid belt, jovian
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