Unit 9

  1. Expanding Universe
  2. Doppler Effect – used by scientists to determine the motion of massive groups of stars in space.
  3. Red Light – Moving away from us – waves lengthen
  4. Blue Light – Moving toward us – waves shorten
  5. Big Bang Theory
  6. The universe was once packed into a small, dense space that burst apart in an enormous explosion.
  7. Evidence:
  8. Red light of stars moving away
  9. Cosmic background radiation
  10. Hydrogen and Helium formed clouds which became stars
  11. Larger stars exploded and formed clouds of dust and gas, which later became the different features in our solar system
  12. Light-year – the distance light travels through space in one earth year. Is used to measure distances in space.
  13. Galaxies – huge clusters of stars, gas, and dust that are bound together by gravity.
  14. Spiral – arms of gas spiral out from a densely packed cluster of stars in the middle.
  15. Old and new stars.
  16. Some gas and dust
  17. Barred-Spiral – have a thick bar of stars and gas passing through their centers.
  18. Elliptical – shaped like a stretched circle or oval.
  19. Old stars
  20. Little dust or gas
  21. Irregular – no distinct shape.
  22. New stars.
  23. Contain the most amount of dust and gas verses other galaxies.
  24. Galaxy clusters – multiple galaxies grouped together throughout space.
  25. Dark matter – the space within galaxies and between galaxies that does not emit any radiation.
  26. Gravity
  27. a force of attraction that is universal because every mass exerts a pull on every other mass.
  28. Sir Isaac Newton’s Law of Universal Gravitation
  29. Every object in the universe exerts a gravitational force on every other object.
  30. The size of the gravitational force depends on the masses of the objects.
  31. The size of the gravitational force depends on the distance between objects.
  32. Weight – measure of the force of gravity on your body
  33. Changes throughout the universe as the force of gravity changes.
  34. Mass – describes the amount of matter an object contains
  35. Is the same no matter where in the universe it is measured.
  36. Speed –
  37. The slower an object moves, the quicker it is pulled back to Earth because of gravity.
  38. The faster an object moves, the farther it will go before it hits Earth.
  39. Rotation and Revolution
  40. Revolution
  41. The faster an object moves, the farther it will go before it hits earth
  42. One revolution of the planet around the sun equals one year on that planet.
  43. Most planets orbit the sun in a slightly elliptical, or oval, path.
  44. Rotation
  45. As a planet revolves around the sun, it is also spinning on its axis
  46. Axis – an imaginary line that runs through the center of the object.
  47. One complete rotation on an axis is equal to a day on that planet.
  48. The Solar System
  49. Sun- Star at the center which all other pieces of our solar system revolve around
  50. Eight planets
  51. 3 dwarf planets
  52. Moons, asteroids and comets
  53. Stars ARE NOT part of the solar system, they are part of the galaxy
  54. Geocentric System
  55. a model of the solar system with the earth as its center.
  56. Heliocentric Theory
  57. Nicolaus Copernicus - proposed that the sun, and not the earth, is actually in the center of the solar system.
  58. Johannes Kepler - determined that all the planets actually revolve around the sun in elliptical paths, and not in perfect circles.
  59. The Inner Planets
  60. Closest to the sun
  61. Are also known as the terrestrial planets, meaning earth-like.
  62. Planet sizes are similar to each other andare relatively small compared toother planets in our solar system.
  63. Made of rock with metallic cores.
  64. Rotate slowly and do not have rings.
  65. Have few, if any, moons.
  66. Mercury
  67. Closest to the sun
  68. Thin atmosphere
  69. Weak gravity
  70. Many craters because of thin atmosphere
  71. No wind or water
  72. 88 days in a year
  73. Smallest planet
  74. Venus
  75. Second planet from the sun
  76. Dense atmosphere (90 times denser than Earth)
  77. Mostly carbon dioxide
  78. Has mountains, volcanoes and lava
  79. Hottest planet in the solar system
  80. Almost the same size as Earth – “Earth’s twin”
  81. Rotates the opposite direction from the other planets!
  82. Earth
  83. Third planet from the sun
  84. Atmosphere of mostly nitrogen along with oxygen
  85. Sustains planet and animal life
  86. 70% water on the surface
  87. Largest of the inner planets
  88. 1 moon
  89. Mars
  90. Fourth planet from the sun
  91. Atmosphere is mostly carbon dioxide
  92. Iron rich surface makes it look red
  93. Has volcanoes, canyons and polar ice caps
  94. Evidence that there was once liquid water
  95. 1 year is twice as long as Earth
  96. Has seasons
  97. 2 moons
  98. Asteroid Belt
  99. Contains most asteroids - relatively small, rocky object that orbits the sun
  100. Located between Mars and Jupiter
  101. Divides the inner and outer planets
  102. Outer Planets
  103. Called the Gas Giants because they are large balls of gaseous elements and clouds with no solid surface.
  104. Arevery large, and because of their increased distances from the sun, are much colder than the inner planets.
  105. Rotate very fast and have complex rings.
  106. Are less dense compared to the solid surfaces of the inner planets.
  107. Usually have many moons.
  108. Jupiter
  109. Fifth planet from the sun
  110. Atmosphere is Hydrogen and Helium – similar to the sun’s
  111. Rotates quickly causing storms on the surface
  112. Red Spot – one huge ongoing hurricane
  113. Largest planet in the solar system
  114. 60 moons – one larger than Mercury!
  115. Saturn
  116. Sixth planet from the sun
  117. Atmosphere is Hydrogen and Helium
  118. Rapid rotation
  119. Very cold
  120. Rings of small dust and ice particles orbit Saturn
  121. Uranus
  122. Seventh planet from the sun
  123. Atmosphere of Hydrogen and Helium
  124. Looks blueish-green
  125. Extremely cold
  126. Axis is on its side
  127. 1 year is as long as 84 Earth years!
  128. Neptune
  129. Eighth and farthest planet from the sun
  130. Windiest planet
  131. Takes 165 Earth years to orbit the sun once
  132. Pluto
  133. Small body of rock and ice – smaller than Earth’s moon!
  134. Orbit is stretched out and on an angle
  135. Not a planet anymore because a planet must:
  136. orbit the sun,
  137. be nearly spherical in shape
  138. have cleared out debris from the vicinity of its orbit
  139. Pluto did not meet the #3 condition, so it is now considered a dwarf planet