ch 1 astronomy

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Across
  1. 3. an enormous gravitationally bound assemblage of millions or billions of stars
  2. 5. one of the 88 patterns of stars in the sky, often named for a mythological god, hero, or animal
  3. 7. an event in which one body passes in front of another, blocking it partially or completely from view; a specific type of occultation
  4. 11. the average distance from Earth to the sun, equal to about 93,000,000 miles (150,000,000 km)
  5. 13. the height above sea level
  6. 14. the phase of the moon when it is halfway around its orbit from new moon and opposite the sun in the sky; the full disk is illuminated
  7. 15. the angular distance of a celestial object above or below the celestial equator; the celestial sphere equivalent of latitude
  8. 18. the angle between a planet (or moon or other object) and the Sun as seen from the Earth.
  9. 19. Geocentric means Earth-centered. In a geocentric model of the universe, everything revolves around the Earth; this, of course, is a false model.
Down
  1. 1. A light-year is the distance that light can travel in one year in a vacuum, which is about 5,880,000,000,000 miles or 63,240 AU or 9.46053 x 1012 kilometers.
  2. 2. the phase of the moon between first quarter and last quarter, when the moon appears more than half illuminated
  3. 4. the imaginary projection of Earth’s rotational axis onto the celestial sphere
  4. 5. the apparent sphere of the sky; an imaginary sphere of immense radius centered on Earth often used to plot the coordinates of objects in the sky
  5. 6. the time of year around September 23 when the sun crosses the celestial equator heading south
  6. 8. the branch of astronomy that deals with the physical characteristics of celestial objects
  7. 9. a solar eclipse in which the moon does not fully cover the sun’s disk, allowing observers to see a thin ring of sunlight
  8. 10. the phase of a planet or moon during which less than half the surface is illuminated
  9. 12. the imaginary projection of Earth’s equator onto the celestial sphere
  10. 16. the plane of Earth’s orbit around the sun; all the planets except Mercury and Pluto have orbits in nearly the same plane
  11. 17. the outer atmosphere of the sun or a star