Wonders Of The Sky 2009 Dark Sky 02


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Wonders Of The Sky 2009 Dark Sky 02

  1. 1. Wonders of the Sky
  2. 2. Wonders of the Dark Sky
  3. 3. Twinkling: Star Scintillation <ul><li>Why do stars twinkle? Stars twinkle because their light is distorted as it passes through earth’s atmosphere </li></ul><ul><li>Also termed scintillation </li></ul><ul><li>The steadiness of air is termed seeing </li></ul><ul><li>Seeing is poor if stars appear to twinkle to the unaided eye </li></ul>
  4. 4. Star Scintillation (twinkling) <ul><li>Images of a single star </li></ul><ul><li>Ideal star resembles a “bull’s eye” pattern </li></ul><ul><li>Atmospheric Refraction </li></ul><ul><li>Objects low in the sky appear with rainbow tints </li></ul><ul><li>Atmosphere distorts light from objects like a prism into colors </li></ul><ul><li>Mainly views of planets such as Venus in a telescope </li></ul>
  5. 5. Why do Star’s Twinkle? Turbulent air causes a star’s image to distort
  6. 6. Venus Refraction
  7. 7. Star Colors: Big & Little Dippers Where is Polaris?
  8. 8. Orion Betelgeuse Rigel <ul><li>Look for these star colors when you see Orion </li></ul>Belt Sword Orion Nebula in Sword of Orion
  9. 10. Meteors <ul><li>Meteors or shooting stars represent the burning (from air friction) in our atmosphere of particles from space </li></ul><ul><li>A particle the size of a grain of sand produces the typical meteor or “shooting star” </li></ul><ul><li>A fireball , a brilliant, shadow casting meteor, is by objects as large as a basketball </li></ul><ul><li>A bolide is a fireball that appears to break apart during flight </li></ul><ul><li>Some bolides have been reported to emit rumbling or booming sounds </li></ul>
  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 <ul><li>A meteorite, a fragment of the Peekskill bolide, penetrated the trunk of this car </li></ul><ul><li>The actual meteorite is displayed below the car </li></ul>
  15. 16. Meteor Showers <ul><li>Meteors are visible every night, these are termed sporadics </li></ul><ul><li>Other meteors fall in predictable showers </li></ul><ul><li>Meteor showers are produced when the earth passes through the trail of debris cast off by a comet </li></ul><ul><li>Earth passes through these trails on the same evenings each year </li></ul>
  16. 17. Radiant <ul><li>Meteor showers are named for the constellation from which the meteors appear to originate </li></ul><ul><li>For example, Perseid meteors originate from the constellation Perseus </li></ul><ul><li>The exact point of origin is termed the radiant </li></ul>
  17. 18. Shower Origins <ul><li>Meteor showers occur on the same evenings each year as the earth passes through the debris shed by comets </li></ul>
  18. 19. Leonid Meteor Shower
  19. 20. “ Falling Stars” & Sirius http://www.astropics.com/leonids/l01nsf.htm Sirius is the night sky’s brightest star
  20. 21. Leonid Radiant
  21. 22. Meteor Videos <ul><li>Alberta Meteor 2008 </li></ul><ul><li>Peekskill, NY Meteor 1992 </li></ul>
  22. 23. Forecast: Meteor Showers <ul><li>Main Meteor Showers </li></ul><ul><li>Quadrantids—Jan 03 </li></ul><ul><li>Lyrids—Apr 21 </li></ul><ul><li>Eta Aquarids—May 04 </li></ul><ul><li>S. Delta Aquarids—July 29 </li></ul><ul><li>Perseids—Aug 11-12 </li></ul><ul><li>Orionids—Oct 20 </li></ul><ul><li>Leonids—Nov 17 </li></ul><ul><li>Geminids—Dec 13-14 </li></ul>
  23. 24. Leonid Meteor Storm <ul><li>One annual shower, the Leonids , has the potential to produce immense meteor storms </li></ul><ul><li>During a meteor storm , thousands of meteors per hour occur </li></ul><ul><li>Leonid storms can occur every 33 years, and the last occurred in the late 1990s </li></ul>http://www.mreclipse.com/Meteors/Leo01/image/Leonid1833-1x.GIF
  24. 25. Dust in the Solar System: Zodiacal Light <ul><li>In certain seasons, a faint, pyramid-shaped glow is visible above the horizon which is termed the zodiacal light </li></ul><ul><li>The Zodiacal light is visible along the ecliptic, the region of the zodiacal constellations </li></ul><ul><li>This glow results from sunlight reflected from dust in the solar system’s plane </li></ul><ul><li>Also known as the false dawn </li></ul>
  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 <ul><li>Note the zodiacal light in the left of this all-sky image </li></ul><ul><li>The Milky Way is visible stretching from upper right to lower left </li></ul>
  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 <ul><li>The gegenschein is also an effect created by solar system dust </li></ul><ul><li>Gegenschein is German for “counterglow”, it is a brightening of the sky in the direction exactly opposite the sun </li></ul><ul><li>Extremely dim and difficult to observe </li></ul>http://www.astrosurf.org/lombry/Documents/gegenschein-15mar1980.jpg
  31. 32. <ul><li>This all-sky image shows the gegenschein, zodiacal light, and Milky Way </li></ul>
  32. 33. Comets <ul><li>Comets are icy bodies from the outer solar system </li></ul><ul><li>When near the sun, comets emit tails of particles and gas </li></ul><ul><li>Appear as glowing shapes in the night sky </li></ul><ul><li>Appear to move against stars in background </li></ul>
  33. 34. Dusty Comet (McNaught) Comet McNaught, January 2007
  34. 35. Comet Lulin (2009)
  35. 36. Comet Holmes (2007) <ul><li>Comet Holmes developed a huge gas cloud (coma), that became larger in volume than the sun </li></ul>
  36. 37. Comet Holmes in Perseus
  37. 38. Comet Hyakutake (1996)
  38. 39. Northern Lights <ul><li>The northern lights or aurora borealis is one of the most dramatic of the sky wonders </li></ul><ul><li>Usually visible from high latitudes ( Link ) </li></ul><ul><li>Can be seen rarely from cont. United States </li></ul><ul><li>Results from glowing gases created by the interaction of earth’s atmospheric gases and radiation from the sun (solar wind) </li></ul>http://www.thisisthelife.com/photos/experiences/large/aurora-borealis.jpg
  39. 40. Appearance of Aurora <ul><li>Resemble light shows that ripple and swirl like waving curtains or billowing plumes of colored smoke </li></ul><ul><li>Usually green in color, range from gray, to green, to red </li></ul><ul><li>Each color represents a different gas; oxygen is green, nitrogen is red </li></ul>
  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 <ul><li>Airglow is a very dim glow present all through the atmosphere </li></ul><ul><li>It is created by a process similar to the northern lights </li></ul><ul><li>Airglow can be identified in long-exposure photos of the sky </li></ul><ul><li>The all-sky view at right was taken in Hawaii, the airglow is visible as streaks </li></ul>
  47. 49. Bands of Airglow
  48. 50. Airglow from Space <ul><li>Airglow is visible as a green layer in this photo from space </li></ul>
  49. 51. Airglow from ISS
  50. 52. The Best Dark Sky Sight: The Milky Way <ul><li>From a dark sky, the Milky Way is a naked eye spectacle </li></ul><ul><li>Appears as a delicate, misty band of light that arches the sky </li></ul><ul><li>Bright glowing clouds and dark lanes are also visible in the Milky Way band </li></ul><ul><li>MW represents the light of thousands of stars too faint to be seen directly </li></ul><ul><li>MW is our view from within our galaxy </li></ul><ul><li>Using a telescope, Galileo discovered that the Milky Way was composed of stars in 1609 </li></ul>
  51. 53. Milky Way Starfields
  52. 54. Summer MW <ul><li>The Milky Way arches across the entire sky during early evening in summer </li></ul><ul><li>The photo shows a view to the southwest in late summer </li></ul>
  53. 55. Home Galaxy <ul><li>How our galaxy would appear from space </li></ul>Looking straight down on the Milky Way All-sky MW photo from Hawaii
  54. 56. Whole Sky View, Hawaii <ul><li>The galaxy’s center lies in the center of this all-sky image </li></ul><ul><li>Note the faint zodiacal band running horizontally through the center of the image </li></ul>
  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 <ul><li>Most celestial objects (galaxies, star clusters, nebulas) require a telescope to be seen </li></ul><ul><li>A few of these objects are bright enough to be seen with the naked eye </li></ul><ul><li>Objects : </li></ul><ul><ul><li>Beehive Cluster </li></ul></ul><ul><ul><li>Pleiades </li></ul></ul><ul><ul><li>Double Cluster </li></ul></ul><ul><ul><li>Orion Nebula </li></ul></ul><ul><ul><li>Andromeda Galaxy </li></ul></ul>
  58. 60. Beehive Cluster (M44) <ul><li>A bright star cluster located in the constellation Cancer </li></ul><ul><li>Resembles a swarm of bees when seen in binoculars </li></ul><ul><li>To the eye, appears as a glowing spot in the sky </li></ul><ul><li>Romans used it as a predictor of weather. If invisible, meant rain was coming </li></ul><ul><li>M44 is an open star cluster containing 200 stars. It is located 515 light years from earth </li></ul><ul><li>Next Slide : Beehive visible to upper right of eclipsed sun </li></ul>
  59. 61. M44 and Eclipse
  60. 62. Cancer Star Map <ul><li>Cancer the Crab is a spring season constellation </li></ul>
  61. 63. Pleiades: Seven Sisters <ul><li>A bright star cluster located in the constellation Taurus </li></ul><ul><li>Resembles a tiny “little dipper” (real LD is Ursa Minor). About 7 stars visible to naked eye </li></ul><ul><li>Celebrated since ancient times, appears in mythology of many cultures </li></ul><ul><li>Open star cluster containing about 100 stars. Located 407 light years from earth </li></ul>
  62. 64. Seven Sisters
  63. 65. Pleiades Deep Image
  64. 66. Taurus Star Map <ul><li>Taurus the Bull is a winter constellation </li></ul><ul><li>The bright star Aldebaran marks the eye of the Bull </li></ul>
  65. 67. “ Taurus” Cave Painting <ul><li>Cave painting in Lascaux, France </li></ul><ul><li>Thought to represent Taurus with Pleiades at upper right of Bull </li></ul><ul><li>Estimated age of painting, 14,000 BC </li></ul>
  66. 68. Perseus Double Cluster <ul><li>Twin open star cluster located in constellation Perseus </li></ul><ul><li>Bright glowing shape in night sky, telescope reveals countless stars </li></ul><ul><li>Located about 7000 light years from earth </li></ul>
  67. 69. Perseus Star Map <ul><li>Perseus is an autumn constellation </li></ul><ul><li>In mythology, Perseus slew the snake-haired Medusa </li></ul><ul><li>The Double Cluster is labelled “h + x” in upper right </li></ul><ul><li>The Double Cluster is easy to spot between Perseus and the “W” of Cassiopeia </li></ul>
  68. 70. Andromeda Galaxy <ul><li>Our nearest large neighbor galaxy </li></ul><ul><li>Similar in size and shape to Milky Way </li></ul><ul><li>Andromeda Galaxy is visible to the naked eye as a glowing spot in the constellation of Andromeda </li></ul><ul><li>Galaxies like Andromeda and our Milky Way are composed of billions of stars </li></ul><ul><li>2.3 million light years distant (wave!) </li></ul>
  69. 71. Andromeda Constellation Locate M31 and M33
  70. 72. Andromeda Spiral
  71. 73. Orion Nebula <ul><li>Bright nebula (glowing cloud of gas) located below Orion’s Belt </li></ul><ul><li>Represents a place where stars are born </li></ul><ul><li>Nebula located a bit over 1300 light years from earth </li></ul>
  72. 74. Orion’s Sword <ul><li>Orion is a winter constellation </li></ul><ul><li>Note bright stars Betelgeuse (upper left) and Rigel (lower right) </li></ul>
  73. 75. Orion Psychedelic
  74. 76. Light Pollution <ul><li>Stargazing is difficult in the city </li></ul><ul><li>Excess artificial light that enters the night sky is termed light pollution </li></ul><ul><li>Observatories are built in remote places away from cities if possible </li></ul>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