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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 http://www.astropics.com/leonids/l02bd.htm
  11. 12. Leonid Meteor & Pleiades http://www.astropics.com/leonids/l01ss.jpg
  12. 13. Fireballs http://www.southdowns.org.uk/images/fireballB.jpg
  13. 14. Peekskill Bolide http://starchild.gsfc.nasa.gov/Images/StarChild/solar_system_level2/fireball_big.gif 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 http://www.astropics.com/leonids/l01nsf.htm 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
    http://www.mreclipse.com/Meteors/Leo01/image/Leonid1833-1x.GIF
  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 http://epod.usra.edu/archive/images/img_3491-1.jpg
  27. 28. Zodiacal Light in Gemini http://www.allthesky.com/various/preview/zodiacgeminim-p.jpg 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 http://www.arizonaskyvillage.com/assets/images/autogen/a_Copy_of_Zodiacal_Light___milkyway.jpg 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
    http://www.astrosurf.org/lombry/Documents/gegenschein-15mar1980.jpg
  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)
    http://www.thisisthelife.com/photos/experiences/large/aurora-borealis.jpg
  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 http://www.livingwilderness.com/patterns/nlights2.html
  43. 44. Wow! http://www.eielson.af.mil/library/news/05nsvs/feb05/Feb_4/Aurora%20borealis.jpg
  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 http://antwrp.gsfc.nasa.gov/apod/ap970517.html
  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
    http://www.apstas.com/astrotas/glow.jpg
  75. 77. Light Pollution: Got Stars? http://www.spaceweather.com/swpod2003/20aug03/Carlson1.jpg
  76. 78. Light Pollution near Tenerife, Canary Islands
  77. 79. Earth at Night (Click Below) http://veimages.gsfc.nasa.gov//1438/earth_lights_lrg.jpg