1. Define Star (Pg 352) Chapter 10 What We Know About the Universe Has Taken Us Thousands of Years to Learn A celestial body of hot gases with a nuclear furnace at its core that makes its own thermal energy. May 17 7:47 PM May 17 7:48 PM 2. Define Celesal Body (Pg 352) A natural object in space, such as the sun, the moon, a planet or a star. 3. How did people thousands of years ago use the movement of celesal bodies to help them? (Pg 352) They used the movement of celestial bodies as a calendar to tell them when to plant crops and when to harvest them. They also used the celestial bodies for navigation. Stonehenge recorded the rising and setting positions of the Sun and Moon at the height of each season. In addition, the oldest stone at the site, called the Heel Stone, was placed at the entry to Stonehenge in such a position that sighting it from the center of the monument points directly to the summer solstice May 17 7:52 PM May 17 7:58 PM 4. a) Define Constellaon (Pg 354) A distinctive pattern in the night sky formed by a group of stars; the pattern often looks like a familiar object, like an animal. b) Define Asterism (Pg 354) A star pattern that is not a constellation; may consist of a small group of stars within a constellation or individual stars from different constellations. May 17 8:05 PM May 17 8:10 PM 1
5. Where did many of the constellaons get their names? (Pg 354) Characters from Greek and Roman mythology or in some cases simply things that were familiar to them. 6. Define Planet (Pg 354) A celestial body that orbits one or more stars, is large enough that its own gravity holds it in a spherical shape and is the only body occupying its orbital path. May 17 8:15 PM May 17 8:24 PM 7. How many constellaons are there according to The Internaonal Astronomical Union? (Pg 354) According to the IAU there are 88 constellations. 8. How many constellaons are visible in Canada? Why? (Pg 355) There are only 68 visible constellations in Canada because there are 20 which never rise above our horizon. May 17 8:31 PM May 17 8:40 PM 9. Idenfy the following constellaons and give the descripon of each. (Pg 354 355) Name: Cassiopea Descripon: The Queen Name: Orion Descripon: The Hunter May 17 8:45 PM May 17 8:46 PM 2
Name: Ursa Major Descripon: The Great Bear or Big Dipper (common name) Name: Leo Descripon: The Lion May 17 8:46 PM May 17 8:47 PM 10. What do the Big Dipper's end or "pointer" stars point toward? (Pg 355) The Big Dipper's pointer stars point toward the North Star. 11. What is the name of this star? Is it the brightest star in the sky? (Pg 355) The North Star is also called Polaris and it is not the brightest star, contrary to popular belief. 12. in what direcon to stars seem to move? (Pg 358) Stars seem to move from east to west. 13. Are the stars actually moving? What causes this movement? (Pg 358) The stars are not really moving. We are moving because the Earth rotates on its axis. May 17 8:47 PM May 17 8:50 PM 14. Define Circumpolar Constellaons (Pg 358) A constellation that never seems to "set", or dip below the horizon; this classification depends upon the viewer. 15. Define eclipc. What follows this type of path? (Pg 359) The path followed by the Sun through the sky, as seen from the Earth. Obviously the Sun follows this path. May 17 8:51 PM May 17 8:53 PM 3
16. Define zodiacal constellaons (Pg 359) Twelve star groups that form the patterns of the zodiac signs: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius and Pisces; twelve stations along the ecliptic. 17. How long does it take the earth to circle the sun? (Pg 360) It takes one year for the Earth to orbit the Sun. May 17 9:00 PM May 17 9:05 PM 18. How are the moons of asteroids and comets different? (Pg 360) Asteroids between Mars and Jupiter move the same way as the planets, while comets can have orbits above or below the orbit of Earth. In other words, asteroids orbit in one plane, while comets can orbit in different planes. Oct 6 9:51 AM May 17 9:08 PM 21. a) Why did Aristotle believe the Earth was in a fixed posion? 19. How did Aristotle visualize the universe? (Pg 368) Aristotle viewed the universe as being geocentric. 20. Define Geocentric (Pg 368) The Earth is the center of the universe and the Sun, Moon, planets and stars revolve around it. a) Aristotle believed the Earth was in a fixed position because the patterns of the stars in the sky did not change. b) Why did he believe the Earth was a sphere? (Pg 368) b) He believed the earth was a sphere because shadows created by the Moon during a lunar eclipse had curved edges. Also because as you travelled north or south you would see different constellations in the sky. Total Lunar Eclipse February 20, 2008.mp4 May 17 9:11 PM May 17 9:13 PM 4
22. Define heliocentric (Pg 368) The Sun is the center of the universe and planets revolved around it. 24. Who was the first person to accurately measure the diameter of the earth? (Pg 369) Eratosthese of Cyene 23. Which Greek philosopher proposed the heliocentric concept? (Pg 368) Aristarchus of Samos May 17 9:25 PM May 17 9:28 PM 5. Define retrograde moon (Pg 369) An apparent switch in the motion of a celestial body from eastward to westward motion, or vice versa, as viewed from the Earth. 26. Define astrolabe (Pg 371) An ancient instrument used to locate and predict the positions of the Sun, Moon, planets and stars. May 17 9:31 PM May 17 9:36 PM 27. Who proposed that the Earth rotated on its axis as a way of explaining observaons in the heavens? (Pg 371) Nicolaus Copernicus proposed that the earth spun on its axis once daily and revolved around the sun once a year. 28. Define Telescope (Pg 372) An optical device that uses lenses or mirrors to gather and focus light to provide a magnified view. May 17 9:38 PM May 17 9:39 PM 5
29. Who invented the telescope? (Pg 372) Galileo invented the telescope, which he used to observe craters on Moon, spots on the Sun and four "stars" orbiting Jupiter. 30. What made Galileo believe the universe was heliocentric? (Pg 372) Galileo believed the universe was heliocentric because he observed that Venus had phases just like the moon. He believed Venus could only have phases if it orbited the Sun. May 17 9:46 PM May 17 9:47 PM 31. How did each of the following add to our understanding of the solar system: Tycho Brahe (Pg 377) Made accurate observations of the positions of planets. Johannes Kepler (Pg 377) Three laws of planetary motion: 1. All planets move in ellipses around the Sun. 2. Planets DO NOT move at a constant speed (faster closer to the Sun) 3. Time it takes for a planet to move around the Sun is in direct proportion to its distance from the Sun. May 17 9:54 PM May 17 9:56 PM Isaac Newton (Pg 378) Newton showed that gravity extends beyond the Earth's surface and affects celestial bodies causing them to remain in orbit around larger bodies. Newton's laws are used when we send spacecraft into space and they govern the motion of stars throughout the Milky Way. He also invented the reflecting telescope. May 17 10:12 PM Sep 28 3:05 PM 6
Attachments Total Lunar Eclipse February 20, 2008.mp4 Satellite Orbital Mechanics Kepler's Laws.mp4