Soar system
- 1. Chapter 18: Section 1 Astronomy Astronomy- the study of the universe Year- time for the earth to orbit around the sun Month- time for the moon to orbit once around the earth - Came from the word “moon” Day- time for the earth to rotate once on its axis
- 2. Ptolemy: An earth- Centered Universe Earth was the center of universe and other planets and sun revolved around the Earth
- 3. Copernicus: A Sun- Centered Universe Sun is the center of the universe and all planets including earth orbit the sun.
- 4. Tycho Brahe (TIE koh BRAW uh) : Wealth of Data Brahe recorded very accurate observations of the movement of bodies in the solar system.
- 5. Johannes Kepler: Laws of Planetary Motion - used Brahe’s data . -all planets revolve around the sun in elliptical orbits - Stated the 3 laws of planetary motion still used today
- 6. Galileo: Turning a telescope to the sky Galileo proved that planets, moon and sun are physical bodies like Earth.
- 7. Isaac Newton: Laws of Gravity All objects in the universe attract each other through gravity. His work helped explain why planets orbit the sun and moons orbit planets.
- 8. Edwin Hubble: Beyond the Edge of the Milky Way In 1924, he proved that other galaxies existed beyond the Milky Way Galaxy.
- 9. Section 2: Telescopes Telescope- instrument that gathers electromagnetic radiation from objects in space and concentrates it for better observation.
- 10. Refracting Telescope - Uses lenses to gather and focus light from distant objects
- 11. Reflecting telescope - Uses a curved mirror to gather and focus light from distant objects
- 12. How does the atmosphere affect the images produced by optical telescopes? The motion of air pollution, water vapor and light pollution distort the images produced by optical telescopes
- 13. To avoid interference in the atmosphere, scientists put telescopes in space. Ex. Hubble Space Telescope- can detect very faint objects in space.
- 14. Electromagnetic Spectrum: All wavelengths of electromagnetic radiation Radiation that can pass through the atmosphere includes radio waves, microwaves, infra red light and ultraviolet light.
- 15. Nonoptical Telescopes: -used to study invisible radiation Ex. Radio Telescopes- detect radio waves
- 16. Nonoptical telescopes in space -put in space because most electromagnetic waves are blocked by the earth’s atmosphere ex. Chandra X-ray Laboratory
- 17. Section 3: Mapping Stars Constellations- sections of the sky that contain recognizable star patterns
- 18. As the earth revolves around the sun, location of constellations change from season to season. This sky map shows some of the constellations in the Northern Hemisphere at midnight in the spring. Ursa Major (the Great Bear) is a region of the sky that includes all of the stars that make up that constellation.
- 19. Why are different constellations visible in the Northern and southern hemispheres? Different constellations are visible in the N and S hemisphere because different portions of the sky are visible from the N and s Hemisphere.
- 20. Measuring Distance in space • Stars are much farther away than the planets are. • Light- year is used to measure their distance.
- 21. Light year- Unit of length equal to the distance that light travels in one year I light year= 9.46 trillion kilometers
- 22. How far does light travel in 1 year?
- 23. 9. 46 trillion kilometers