Credit & Copyright: Lance McVay
Explanation:
Some auroras
can only be seen with a camera.
They are called sub-visual and are too faint to be seen with the unaided eye.
The reason is that the human eye
only accumulates light for a fraction of a second at a time,
while a camera shutter can be left open indefinitely.
When photographing an already picturesque scene above
Juneau,
Alaska,
USA,
a camera caught green sub-visual aurora near the horizon.
Auroras
are sparked by
energetic particles from the
Sun impacting the
magnetic environment
around the Earth.
Resultant energetic particles such as
electrons and
protons
rain down near the Earth's poles and impact the air.
The impacted
air molecules
temporarily lose electrons, and when
oxygen molecules
among them reacquire these electrons, they emit
green light.
Auroras
are known to have many
shapes and
colors.
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 |
Yanvar' Fevral' Mart Aprel' Mai Iyun' Iyul' Avgust Sentyabr' Oktyabr' Noyabr' Dekabr' |
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
|
Publikacii s klyuchevymi slovami:
aurora - polyarnoe siyanie - Magnitnoe pole Zemli
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