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Astronomy and Astron
Marano- Astronomy and Astronomers
| Question | Answer |
|---|---|
| astronomy | the study of all physical objects beyond the Earth's atmosphere |
| calendar | system for organizing time based on astronomical observations |
| year | time needed for a planet to make one complete orbit around the sun |
| revolution | one complete orbit |
| How long does it take earth to make one revolution | 365.242 days |
| What is our calendar called? | Gregorian |
| Leap year | happens every four years, add 1 day to calendar |
| Month | time needed for moon to orbit the Earth |
| day | time needed for a planet to turn itself on its axis of rotation |
| Angle of earth's rotation | 235 degrees |
| How long does it take for the earth to make one rotation? | 24 hours |
| Why do we have day and night? | only half the Earth can face the sun and have daylight |
| Ptolemy | Geocentric model- earth is center of universe |
| Copernicus | Heliocentric- sun is the center of the universe |
| Brahe | Believed that planets revolve around sun, but sun and moon revolve around Earth |
| Kepler | believed that planets revolve around sun in elliptical orbits |
| Galileo | first person to use telescope |
| Newton | Gravity is the force that keeps all objects in orbit |
| Newton's law of universal gravitation | the higher the gravity, the more mass or the closer objects are together |