AURORA [POLARIS]

The Northern Lights (aurora borealis) and the Southern Lights (aurora australis)


As seen from the Space Shuttle:

Internet Resources
The Aurora Page of the Poker Flats Rocket Range is a good launch pad into auroral cyberspace
Aurora's Northern Lights site by Jan Curtis with links to photos and other stuff
University of Oulu's Aurora Page
Another Finnish website with articles on myth, history, etc.
Space Environment Center's pdf file on Aurora
Windows to the Universe Aurora page
Michigan Tech University's Aurora Links Page
UCAR's (University Corporation for Atmospheric Research) Physics of the Aurora webcast
A brief YouTube video from the University of Oslo
An "old-fashioned" source (a book): Majestic Lights by Robert Eather; on-line preview
PBS Nova program At the Edge of Space airing on Nov 20, 2013 (last eight minutes about aurora)

MOST RECENT MAPS of the position and extent of the northern and southern auroral ovals

The Luminous Aurora

PHOTOGRAPHY

Internet Resource:
Tips on Photographing the Aurora from Brian Rachford and Jan Curtis
Interview with photographer Heather Jones from Carcross Yukon.
Photographers' Voice
Pekka Parviainen's Polar Image site
A video clip from BBC FOUR
Lots of nice video clips on YouTube. To start: A realtime clip from Norway on the night of the 24/25th of January 2012. More
National Geographic Magazine
top shot from July 2008 and another NGM photo
See November 2001 feature article on auroras in National Geographic Magazine.
Photo from near Glens Falls NY taken evening of Nov 13/14, 2012. Following shot is from Saratoga Springs

Historical outline of Auroral Imaging
20,000 B.C.earliest depictions(?): Serpertine meanders (macaronis) in cave drawings by Cro-Magnon
1575First published scientific illustration by Cornelius Gemma
1885Sophus Tromholt attempts photography; gets a blurry blob after 8 minute exposure
1892Martin Brendel obtains first useful (B&W) photographs
1910-43Carl Störmer takes thousands of photos
1913Störmer records movie (4 seconds per frame)
1940Störmer begins unsuccessful attempts at color photography
1951Gartlein and Petrie present color photos at Auroral Conference in London, Canada
June 1953Life Magazine publishes color photos
1968Imaging with orbiting satellites begins
1970'sColor movies become practical with availability of high-speed color film
1980'sSignificant improvements due to low light television technology

International Brightness Coefficient
CoefficientAppearanceEquivalent to:Brightness
IBC0subvisual < 1 kRa
IBC1appears whiteMilky Way 1 kRa
IBC2onset of color perceptionThin moonlit cirrus 10 kRa
IBC3bright stars don't shine throughMoonlit cumulus 100 kRa
IBC4casts shadowsFull moonlight 1000 kRa

HISTORICAL RECORD

Ancient chroniclers described what are now known as aurorae in various terms including flaming heavens, cracks in the heavens, burning clouds, fire dragons, and heavenly armies or battles. Sometimes it is difficult to discerned whether other phenomena (meteors, comets, St. Elmo's fire) are actually being described.
ca. 2600 BCPossibly first written description in Bamboo Album of Chronology (Chu-Shu-Chi-Nien)
8th c. BCHesiod in Theogony describes flaming heavens, fiery sky dragons
687 BCFirst aurora listed in Chinese historical catalogs (through to the 10th c. AD)
ca. 460 BCMention in histories of Livy and Dionysius (Roman)
ca. 340 BCInfiltration during night of the army of Philip of Macedonia into the city of Byzantium reputably foiled by light from aurora
37 ADTiberius mistakenly sends Roman army to put out fire seen on the horizon
555Earliest mention in England by Mathew of Westminster
919Earliest event known in written Russian record
1100's regular observers (Mathieu of Edesse - Middle East; Vysehrad - Prague; Gervasius - England)
1111Victory of outnumbered Russian army over Polovtsy attributed to appearance of aurora behind the Russians
[The dance, The Voice (English subtitles with a little rap), Bennett]
1192Great Aurora of 1192
1200-1500 few recorded auroral sightings due to warfare (e.g. Mongol threat, Crusades), plague (Black Death), religious dogma (generally a bad time had by all)
1400-1500 Spörer Minimum (little solar activity)
1500'sRenewed auroral activity reported in Europe
1643First sighting with known written report in North America (by John Winthrop, Governor of Massachusetts)
1645-1715 Maunder Minimum (little solar activity)
3/17/1716 Great Aurora over Europe
1719 Bright aurora over New England and China
9/2/1859 Brightest aurora ever reliably reported occurs day after Carrington discovers solar flare

Historical Auroras
List of some great aurora and recent bright displays
another list with links to contemporary newspaper reports.

CULTURAL IMPACT

In locations of common occurrence aurora was incorporated into myth and legend. In places where aurorae occur rarely, they were often associated with significant events or considered omens (usually of the ill-tempered variety)

Aurora as Omen

Some events that have been associated with the appearance of an aurora:
44 BCThe assassination of Julius Caesar
1st c. ADPliny the Elder describes earlier aurorae as "presage of woe"
451The defeat of Attila at Catalaunic Fields
566The invasion of Italy by Lombards in 568; aurora receives moniker "acies igneae" (battle lines of fire)
566The birth of Mohammed in 570
793Anglo-Saxon Chronicles notes "this year dire forewarnings came over the land"
1170The blood of Thomas à Becket rising to heaven
1177Temujin (Genghis Khan) took as sign that he would unite Mongols and conquer the world
Jan 15,1192Famine of 1197 in Europe
Nov 14,1574Earthquake on Feb 26,1575
March 6,1716The execution of Lord Derwentwater (Jacobite uprising)
NORTHERN LIGHTS, The Story of Lord Derwentwater
Oct 8,1728Earthquakes in Sicily and England
Jan. 25, 1938World War II

Aurora in Legend and Folklore

See these brief on-line descriptions:
Auroral Folklore
Various Beliefs
Aurora in Eskimo Legend
Native American Legend and Folklore

Possible source of Greek myth of Mount Olympus as home of the Gods
Probably only instance where the aurora is actually a deity (god of birth) is among the Chuvash, an ethnic group with a republic in the Russian Federation

Possible Biblical References

The Arts

AURORAL FORMS and TYPES

Auroral Forms:

The visible aurora extends vertically along magnetic field lines often for tens of miles and horizontally east-west for hundreds of miles, but the auroral feature is usually only 100 yards or so thick (north-south). The shape or form of an aurora therefore is dependent on the perspective of the observer.

Auroral Types:

AURORA PHYSICS

Main topics of auroral research involve determining and understanding:

A crude analogy
like a television:

Another crude analogy
like a toaster:

The following excerpt is from The Auroral Particles and Imagery Group at The Johns Hopkins University Applied Physics Laboratory (JHU/APL)
The Earth wears a halo around each magnetic pole. The halo is visible to the naked eye (well, at least to an astronaut above the poles) near winter solstice, and can be observed any time in ultraviolet (uv). This ring, called the auroral oval, divides the Earth's magnetic field lines into two types:

At the interface between open and closed field lines dramatic plasma physics processes occur, including the ring of light forming the auroral oval.

Auroral Oval versus Auroral Zone

The Auroral Oval: the instantaneous position of luminosity below which the Earth rotates. Typically around 67 degrees geomagnetic latitude around midnight and moving to 78 degrees geomagnetic latitude at midday. The picture below shows the auroral oval in winter approaching midnight in Albany, NY

The Auroral Zone: the position of maximum probability of observing auroral luminosity. Viewing conditions are best around midnight and the aurora also tends to be brighter in this section of the oval. Consequently the highest probability of viewing aurora occurs around the geomagnetic latitude of 67 degrees

Note that the Auroral Zone passes through central Alaska, but in the picture below taken just after sunset in Alaska, the Auroral Oval lies to the north. The aurora may be visible at this latitude only during winter; at other times of the year the aurora is not usually visible here because of daylight. The Auroral Oval will pass over central Alaska later in the evening.

Other notes:

OTHER AURORAL PHENOMENA (non-luminous)