1.Aurora, United States
Wonder: Aurora
Country: United States
Region: Alaska
Visitable: Yes
About:
Natural colored light displays in the sky, usually observed in the polar zone at night. Often it appears as a greenish glow rising from an unusual direction extending in east-west.
Aurorae are natural colored light displays in the sky which are usually observed in the polar zone at night. They occur in the ionosphere in this way some scientists call them “polar auroras”. The effect is known as the aurora borealis in northern latitudes, “Aurora” is for Roman goddess of dawn and “boreas” is for Greek name for north wind. Also called the northern polar lights because it is only visible in the Northern sky from the Northern Hemisphere and it most often occurs from September to October and from March to April. The Cree call it the “Dance of the Spirits”. In southern parts is called aurora australis or southern polar lights with similar properties, “australis” is the latin word for “of the south”.
On August 28, 1859 and September 2, 1859 as a result of the “great geomagnetic storm” are produced the auroras, the most spectacular ever witnessed throughout recent recorded history. Probably the aurora was produced by one of the most intense coronal mass ejections in history, very near to the maximum intensity of the sun. Some telegraph lines seem to have been of the appropriate length and orientation which allowed a current to be induced in them and actually used for communication. The following conversation occurred between two operators around two hours using no battery power at all and working solely with the current induced by the aurora.
Thursday, December 24, 2009
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