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Wonders Of The Sky 2009 Dark Sky 02

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  1. 1. Wonders of the Sky
  2. 2. Wonders of the Dark Sky
  3. 3. Twinkling: Star Scintillation
    • Why do stars twinkle? Stars twinkle because their light is distorted as it passes through earths atmosphere
    • Also termedscintillation
    • The steadiness of air is termedseeing
    • Seeing is poor if stars appear to twinkle to the unaided eye
  4. 4. Star Scintillation (twinkling)
    • Images of a single star
    • Ideal star resembles a bulls eye pattern
    • Atmospheric Refraction
    • Objects low in the sky appear with rainbow tints
    • Atmosphere distorts light from objects like a prism into colors
    • Mainly views of planets such as Venus in a telescope
  5. 5. Why do Stars Twinkle? Turbulent air causes a stars image to distort
  6. 6. Venus Refraction
  7. 7. Star Colors: Big & Little Dippers Where is Polaris?
  8. 8. Orion Betelgeuse Rigel
    • Look for these star colors when you see Orion
    Belt Sword Orion Nebula in Sword of Orion
  9. 10. Meteors
    • Meteors or shooting stars represent the burning (from air friction) in our atmosphere of particles from space
    • A particle the size of a grain of sand produces the typicalmeteoror shooting star
    • Afireball , a brilliant, shadow casting meteor, is by objects as large as a basketball
    • Abolideis a fireball that appears to break apart during flight
    • Some bolides have been reported to emit rumbling or booming sounds
  10. 11. Leonid Meteor & Big Dipper
  11. 12. Leonid Meteor & Pleiades
  12. 13. Fireballs
  13. 14. Peekskill Bolide This bolide scattered several meteorites across the northeastern United States
  14. 15. Meteorite 1, Car 0
    • A meteorite, a fragment of the Peekskill bolide, penetrated the trunk of this car
    • The actual meteorite is displayed below the car
  15. 16. Meteor Showers
    • Meteors are visible every night, these are termedsporadics
    • Other meteors fall in predictable showers
    • Meteor showersare produced when the earth passes through the trail of debris cast off by a comet
    • Earth passes through these trails on the same evenings each year
  16. 17. Radiant
    • Meteor showers are named for the constellation from which the meteors appear to originate
    • For example, Perseid meteors originate from the constellation Perseus
    • The exact point of origin is termed theradiant
  17. 18. Shower Origins
    • Meteor showers occur on the same evenings each year as the earth passes through the debris shed by comets
  18. 19. Leonid Meteor Shower
  19. 20. Falling Stars & Sirius Sirius is the night skys brightest star
  20. 21. Leonid Radiant
  21. 22. Meteor Videos
    • Alberta Meteor 2008
    • Peekskill, NY Meteor 1992
  22. 23. Forecast: Meteor Showers
    • Main Meteor Showers
    • QuadrantidsJan 03
    • LyridsApr 21
    • Eta AquaridsMay 04
    • S. Delta AquaridsJuly 29
    • PerseidsAug 11-12
    • OrionidsOct 20
    • LeonidsNov 17
    • GeminidsDec 13-14
  23. 24. Leonid Meteor Storm
    • One annual shower, theLeonids , has the potential to produce immense meteor storms
    • During ameteor storm , thousands of meteors per houroccur
    • Leonid storms can occur every 33 years, and the last occurred in the late 1990s
  24. 25. Dust in the Solar System:Zodiacal Light
    • In certain seasons, a faint, pyramid-shaped glow is visible above the horizon which is termed thezodiacal light
    • The Zodiacal lightis visible along the ecliptic, the region of the zodiacal constellations
    • This glow results from sunlight reflected from dust in the solar systems plane
    • Also known as thefalse dawn
  25. 26. Zodiacal Light
  26. 27. Zodiacal Light & Meteor
  27. 28. Zodiacal Light in Gemini The zodiacal light is found along the zodiac or ecliptic
  28. 29. False Dawn
    • Note the zodiacal light in the left of this all-sky image
    • TheMilky Wayis visible stretching from upper right to lower left
  29. 30. Night Glows Photo from southeast Arizona Right: Milky Way, Left: Zodiacal Light
  30. 31. Dust in the Solar System: Gegenschein
    • Thegegenscheinis also an effect created by solar system dust
    • Gegenschein is German for counterglow, it is a brightening of the sky in the direction exactly opposite the sun
    • Extremely dim and difficult to observe
  31. 32.
    • This all-sky image shows the gegenschein, zodiacal light, and Milky Way
  32. 33. Comets
    • Comets are icy bodies from the outer solar system
    • When near the sun, comets emit tails of particles and gas
    • Appear as glowing shapes in the night sky
    • Appear to move against stars in background
  33. 34. Dusty Comet (McNaught) Comet McNaught, January 2007
  34. 35. Comet Lulin (2009)
  35. 36. Comet Holmes (2007)
    • Comet Holmes developed a huge gas cloud (coma), that became larger in volume than the sun
  36. 37. Comet Holmes in Perseus
  37. 38. Comet Hyakutake (1996)
  38. 39. Northern Lights
    • The northern lights or aurora borealis is one of the most dramatic of the sky wonders
    • Usually visible from high latitudes ( Link )
    • Can be seen rarely from cont. United States
    • Results from glowing gases created by the interaction of earths atmospheric gases and radiation from the sun (solar wind)
  39. 40. Appearance of Aurora
    • Resemble light shows that ripple and swirl like waving curtains or billowing plumes of colored smoke
    • Usually green in color, range from gray, to green, to red
    • Each color represents a different gas; oxygen is green, nitrogen is red
  40. 41. Aurora from Norway
  41. 42. Church,Aurora Borealis , 1865
  42. 43. Red Aurora
  43. 44. Wow!
  44. 45. Norway, March 08
  45. 47. Aurora from Space Shuttle
  46. 48. Airglow
    • Airglow is a very dim glow present all through the atmosphere
    • It is created by a process similar to the northern lights
    • Airglow can be identified in long-exposure photos of the sky
    • The all-sky view at right was taken in Hawaii, the airglow is visible as streaks
  47. 49. Bands of Airglow
  48. 50. Airglow from Space
    • Airglow is visible as a green layer in this photo from space
  49. 51. Airglow from ISS
  50. 52. The Best Dark Sky Sight: The Milky Way
    • From a dark sky, theMilky Wayis a naked eye spectacle
    • Appears as a delicate, misty band of light that arches the sky
    • Bright glowing clouds and dark lanes are also visible in the Milky Way band
    • MW represents the light of thousands of stars too faint to be seen directly
    • MW is our view fromwithinour galaxy
    • Using a telescope, Galileo discovered that the Milky Way was composed of stars in 1609
  51. 53. Milky Way Starfields
  52. 54. Summer MW
    • The Milky Way arches across the entire sky during early evening in summer
    • The photo shows a view to the southwest in late summer
  53. 55. Home Galaxy
    • How our galaxy would appear from space
    Looking straight down on the MilkyWay All-sky MW photo from Hawaii
  54. 56. Whole Sky View, Hawaii
    • The galaxys center lies in the center of this all-sky image
    • Note the faint zodiacal band running horizontally through the center of the image
  55. 57. Lund Milky Way Panorama
  56. 58. Mellinger Panorama
  57. 59. Naked Eye Wonders of the Sky
    • Most celestial objects (galaxies, star clusters, nebulas) require a telescope to be seen
    • A few of these objects are bright enough to be seen with the naked eye
    • Objects :
      • Beehive Cluster
      • Pleiades
      • Double Cluster
      • Orion Nebula
      • Andromeda Galaxy
  58. 60. Beehive Cluster (M44)
    • A bright star cluster located in the constellation Cancer
    • Resembles a swarm of bees when seen in binoculars
    • To the eye, appears as a glowing spot in the sky
    • Romans used it as a predictor of weather. If invisible, meant rain was coming
    • M44 is an open star cluster containing 200 stars. It is located 515 light years from earth
    • Next Slide : Beehive visible to upper right of eclipsed sun
  59. 61. M44 and Eclipse
  60. 62. Cancer Star Map
    • Cancer the Crab is a spring season constellation
  61. 63. Pleiades: Seven Sisters
    • A bright star cluster located in the constellation Taurus
    • Resembles a tiny little dipper (real LD is Ursa Minor). About 7 stars visible to naked eye
    • Celebrated since ancient times, appears in mythology of many cultures
    • Open star cluster containing about 100 stars. Located 407 light years from earth
  62. 64. Seven Sisters
  63. 65. Pleiades Deep Image
  64. 66. Taurus Star Map
    • Taurus the Bull is a winter constellation
    • The bright star Aldebaran marks the eye of the Bull
  65. 67. Taurus Cave Painting
    • Cave painting in Lascaux, France
    • Thought to represent Taurus with Pleiades at upper right of Bull
    • Estimated age of painting, 14,000 BC
  66. 68. Perseus Double Cluster
    • Twin open star cluster located in constellation Perseus
    • Bright glowing shape in night sky, telescope reveals countless stars
    • Located about 7000 light years from earth
  67. 69. Perseus Star Map
    • Perseus is an autumn constellation
    • In mythology, Perseus slew the snake-haired Medusa
    • The Double Cluster is labelled h + x in upper right
    • The Double Cluster is easy to spot between Perseus and the W of Cassiopeia
  68. 70. Andromeda Galaxy
    • Our nearest large neighbor galaxy
    • Similar in size and shape to Milky Way
    • Andromeda Galaxy is visible to the naked eye as a glowing spot in the constellation of Andromeda
    • Galaxies like Andromeda and our Milky Way are composed of billions of stars
    • 2.3 million light years distant (wave!)
  69. 71. Andromeda Constellation Locate M31 and M33
  70. 72. Andromeda Spiral
  71. 73. Orion Nebula
    • Bright nebula (glowing cloud of gas) located below Orions Belt
    • Represents a place where stars are born
    • Nebula located a bit over 1300 light years from earth
  72. 74. Orions Sword
    • Orion is a winter constellation
    • Note bright stars Betelgeuse (upper left) and Rigel (lower right)
  73. 75. Orion Psychedelic
  74. 76. Light Pollution
    • Stargazing is difficult in the city
    • Excess artificial light that enters the night sky is termed light pollution
    • Observatories are built in remote places away from cities if possible
  75. 77. Light Pollution: Got Stars?
  76. 78. Light Pollution near Tenerife, Canary Islands
  77. 79. Earth at Night (Click Below)