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Auroras

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  1. Auroras By: Jennifer Cunningham, Alex Dukes, and Heather Hodnett

  2. Aurora Folklore • Vikings • Finnish • Estonian • Scottish • Latvian • Danish • Sami (Northern Europe) • Algonquin (Canada) • Inuit • Prospectors during Klondike Gold Rush “Valkyrior” of Viking mythology

  3. Earliest Recordings • Cro-Magnon cave-paintings • 30,000 B.C. • Chinese writings • 2600 B.C. Cave painting of aurora phenomenon

  4. Early Scientific Explanations • Norwegian educational text • 1250 A.D. • Scandinavian ideas • Galileo Galilei • 1619 A.D. • Coins term “aurora borealis”

  5. Historical Timeline • ELECTRICAL CURRENT • Hiorter and Celsius, Swedish astronomers (1741) • ALTITUDE • Henry Cavendish, British scientist (1790) • MAGNETISM & MAPPING • Loomis and Fritz (1860 & 1881) • “TERRELLA EXPERIMENT” • Kristian Birkeland, Norwegian physicist (1902-1903)

  6. “Leaky Bucket theory” • Overflow of positive particles from radiation belt? • Disproved in 1962 by James van Allen, American Space Scientist • Auroras caused by excited gas molecules!

  7. Where it All Begins… • Solar Flares • Coronal Mass Ejections (CMEs)

  8. The Collision The Solar Wind vs. Mother Earth

  9. Orientation Day • The earth’s magnetic fields • The polar donuts

  10. The Excitement Builds… O*  O + hv N2+*  N2+ + hv Remember Crystal Field Theory 

  11. The Grand Finale Oxygen atom: 558 nm (green) and 636 nm (red) Nitrogen ion: 391-470 nm (blue, indigo, violet)

  12. Overview • Location • Polar zones • The Northern Lights can be seen in most of Alaska, Canada, and the northern reaches of Europe and Asia • Frequency • Larger shows occur during the three years following the peak of the 11 yr. sunspot cycle • Also larger during the months surrounding the fall and spring equinoxes • The National Oceanic and Atmospheric Administration (NOAA) uses the Polar-orbiting Operational Environmental Satellite (POES) to continually monitor the power flux of the particles that produce the auroras

  13. I Want To See Them! According to http://www.gedds.alaska.edu/AuroraForecast/ • This Monday May 7th, 2007 the Auroras will be fairly active. • They will be able to be seen in the north-east corner of Washington, the northern half of Montana! Field Trip Time!

  14. The Great Auroras of September 2, 1985 • Major solar flares caused huge Auroras • Auroras interrupted most of the 125,000 miles of telegraph lines in the US • A few lines were of just the right length and orientation to capture the storm power • A clear conversation was held for more than two hours between Boston and Portland telegraph stations with no battery power used!

  15. We Are Not Alone… • Jupiter and Saturn have magnetic fields stronger than those on Earth so the auroras are clearly visible • Io, Ganymede, and Europa • Mars • Recent discovery reveals presence of • auroras • The magnetic field failed long ago • The remaining fragments are apparently • enough to form auroras

  16. Sources of Reference • Chemistry Textbook (pages 755 – 756) • Wikipedia http://en.wikipedia.org/wiki/Aurora_%28astronomy%29 • Chemistry & Physics of Auroras http://www.exploratorium.edu/learning_studio/auroras/happen.html • Aurora History http://ds9.ssl.berkeley.edu/themis/mission_aurora.html • Aurora Forecast http://www.gedds.alaska.edu/AuroraForecast

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