science test

  1. what is the universe composed of?
    empty space, energy and matter
  2. most of the universe is _________
    empty space
  3. whawt does matter in the universe include?
    gas molecules, mainly hydrogen, and dust particles
  4. some of this matter had come together to form______
    stars, planets, moons, asteroids, meteoroids and comets
  5. most of these objects can only be seen with a ___
    telescope or other scientific instruments
  6. define stars
    spherical masses of hot gases that produce energy
  7. why do stars look small?
    because they are far away
  8. what units do astronomers use to measure the distance of stars?
    light years
  9. define a light year
    the distance light travels in a year
  10. Is our universe expanding?
  11. most stars and galaxies of stars are moving ________
    away from each other
  12. how old is the sun estimated to be?
    4.5 billion years old
  13. what is the central and largest body of our solar system?
    the sun
  14. what si the nearest star to earth?
    the sun
  15. the sun is considered an _________ sized star
  16. what color is the sun?
  17. what are some features on the sun's surface?
    eruptions called solar flares and sun spots
  18. what are the brightest stars called?
    blue giants
  19. what color are the coolest stars?
  20. compared to a red dwarf, a white dwarf is ________
    hotter and brighter
  21. what is the sun classified as?
    a main sequence star
  22. light, heat, and ultraviolet radiation are types of _______produced be stars
  23. what is the most common gaseous element found in stars?
  24. define planets
    solid bodies which move in definite paths around a central star
  25. what keeps the planets in orbit around the sun?
  26. what are the two types of planets in our solar system?
    terrestrial and jovian
  27. what are the inner planets called?
    terrestrial planets
  28. what are the outer planets called?
    jovian planets
  29. describe the inner planets
    small dense and rocky
  30. describe the outer planets
    large gaseous and have low densities
  31. what are the shapes of planets?
  32. what is the name of the almost (but not quite) circular orbit planets and other objects take around the sun?
    elliptical orbit
  33. jovian planets have _____ moons than terrestrial planets
  34. define asteroids
    large irregular shaped rocks that orbit the sun
  35. what is located between mars and jupiter?
    asteroid belt
  36. define comets
    masses of ice and embeded rock debris
  37. what is the ice fromt eh comets made from?
    water, ammonia, methane, and carbon dioxide.
  38. whwat happens as a comet gets closer to the sun?
    it will begin to warm and vaporize
  39. as the comets melts it leaves behind a trail of ______
    rock debris
  40. what does the rock debris from a comet become?
  41. define meteoroid
    rock fragments in space that can be as big as a boulder or as small as dust
  42. when meteoroids and asteroids hit moons or planets what does it form?
    a crater
  43. define moons
    solid objects which orbit around planets
  44. the phrase "dirty snowball could best describe a_______
  45. what is the smallest planet?
  46. what is the largest planet?
  47. what planet has the longest revolution?
  48. which planet had similar density as earth?
  49. which planet has similar size as earth?
  50. the moon is a ___________ of earth
    natural satellite
  51. what is the period of revolution and rotation?
    27 1/3 days
  52. why does the same side of the moon always face the earth?
    because the rate of rotation and revolution is the same
  53. why do we see the moon?
    because it reflects light off the sun
  54. what causes us to see the moons different phases?
    the moons revolution around earth
  55. what is the order of the planets?
    mercury, venus, earth, mars, jupiter, saturn, uranus, neptune
  56. what is the order of the moons phases?
    new moon, waxing crescent, first quarter, waxing gibbous, full moon, wanning gibbous, last quarter, wanning crescent, new moon
  57. what causes eclipses?
    the interactive movements of the moon and earth relative to the sun
  58. when do eclipses occur?
    when the sun, moon and earth are exactly lined up
  59. what is the order of the moon sun and earth during a solar eclipse?
    the moon is in between the sun and earth (sun, moon, earth)
  60. what is not visible during a solar eclipse?
    the sun
  61. why is the sun not visible during a solar eclipse?
    because the moons shadow falls on earth
  62. what is the order of the moon sun and earth during a lunar eclipse?
    the earth is in between the sun and the moon (sun, earth, moon)
  63. what is not visible during a lunar eclipse?
    the moon
  64. why is the moon not visible during a lunar eclipse?
    because the earths shadows falls on the moon
  65. define tides
    cyclic pattern of water rising and falling along the ocean shoreline
  66. what causes tides?
    the gravitational pull of the moon and sun on the earths ocean
  67. what has more effect on tides, the sun or the moon? why?
    the moon because its closer
Card Set
science test