by APOD Robot » Fri Sep 21, 2012 4:06 am
September Aurora
Explanation: September's
equinox arrives tomorrow as the Sun crosses the celestial equator heading south. The event marks the astronomical beginning of spring in the southern hemisphere and autumn in the north. And though
the connection is still puzzling, the equinox seasons bring an increase in geomagnetic storms. So as northern nights grow longer, the equinox also heralds the arrival of a good season for
aurora hunters. Recorded on September 20,
these colorful northern lights were captured with camera and wide-angle lens near the Norwegian Sea coast outside Tromsø in Northern Norway.
Shining at altitudes of 100 kilometers or so, the aurora rays are parallel, but perspective makes them appear to radiate from a vanishing point behind the silhouetted pine tree. Stars in this enchanting northern night
include Polaris above and right of the tree top, and yellowish giant stars
Shedar (Alpha Cassiopiae) to the left and
Kochab (Beta Ursae Minoris) to the right. Bright
Altair shines through the greenish auroral curtain at the lower left of the scene.
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[url=http://apod.nasa.gov/apod/ap120921.html][img]http://apod.nasa.gov/apod/calendar/S_120921.jpg[/img] [size=150]September Aurora[/size][/url]
[b] Explanation: [/b] September's [url=http://apod.nasa.gov/apod/ap070923.html]equinox[/url] arrives tomorrow as the Sun crosses the celestial equator heading south. The event marks the astronomical beginning of spring in the southern hemisphere and autumn in the north. And though [url=http://science.nasa.gov/science-news/science-at-nasa/2001/ast26oct_1/]the connection[/url] is still puzzling, the equinox seasons bring an increase in geomagnetic storms. So as northern nights grow longer, the equinox also heralds the arrival of a good season for [url=http://apod.nasa.gov/apod/ap120209.html]aurora hunters[/url]. Recorded on September 20, [url=http://nordlysfoto.blogspot.com/2012/09/breath-taking-auroras.html]these colorful northern lights[/url] were captured with camera and wide-angle lens near the Norwegian Sea coast outside Tromsø in Northern Norway. [url=http://odin.gi.alaska.edu/FAQ/#altitude]Shining at altitudes[/url] of 100 kilometers or so, the aurora rays are parallel, but perspective makes them appear to radiate from a vanishing point behind the silhouetted pine tree. Stars in this enchanting northern night [url=http://apod.nasa.gov/apod/ap110514.html]include Polaris[/url] above and right of the tree top, and yellowish giant stars [url=http://stars.astro.illinois.edu/sow/shedar.html]Shedar[/url] (Alpha Cassiopiae) to the left and [url=http://stars.astro.illinois.edu/sow/kochab.html]Kochab[/url] (Beta Ursae Minoris) to the right. Bright [url=http://apod.nasa.gov/apod/ap100625.html]Altair shines[/url] through the greenish auroral curtain at the lower left of the scene.
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