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Auroras. By: Jennifer Cunningham, Alex Dukes, and Heather Hodnett. Aurora Folklore. Vikings Finnish Estonian Scottish Latvian Danish Sami (Northern Europe) Algonquin (Canada) Inuit Prospectors during Klondike Gold Rush. “Valkyrior” of Viking mythology. Earliest Recordings.
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Auroras By: Jennifer Cunningham, Alex Dukes, and Heather Hodnett
Aurora Folklore • Vikings • Finnish • Estonian • Scottish • Latvian • Danish • Sami (Northern Europe) • Algonquin (Canada) • Inuit • Prospectors during Klondike Gold Rush “Valkyrior” of Viking mythology
Earliest Recordings • Cro-Magnon cave-paintings • 30,000 B.C. • Chinese writings • 2600 B.C. Cave painting of aurora phenomenon
Early Scientific Explanations • Norwegian educational text • 1250 A.D. • Scandinavian ideas • Galileo Galilei • 1619 A.D. • Coins term “aurora borealis”
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)
“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!
Where it All Begins… • Solar Flares • Coronal Mass Ejections (CMEs)
The Collision The Solar Wind vs. Mother Earth
Orientation Day • The earth’s magnetic fields • The polar donuts
The Excitement Builds… O* O + hv N2+* N2+ + hv Remember Crystal Field Theory
The Grand Finale Oxygen atom: 558 nm (green) and 636 nm (red) Nitrogen ion: 391-470 nm (blue, indigo, violet)
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
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!
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!
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
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