Pictures and albums about The-polar-aurora published in outdoors

Featured Editor's Collection Autumn Landscapes ~ Featured Member's Choice Fall Scenics October 2007

Featured Member's Choice Outdoors Falls Scenics October 2007 ~ I have entered this photograph on space.com for the category Astrophotos ~ Auroras, and if it is published I will provide the link here!! ~ Source for Aurora information provided below ~ http://odin.gi.alaska.edu/FAQ/#curtain ~ Aurora is a luminous glow of the upper atmosphere, which is caused by energetic particles that enter the atmosphere from above. On Earth, the energetic particles that make aurora come from the geospace environment, the magnetosphere. These energetic particles are mostly electrons, but protons also make aurora. The electrons travel along magnetic field lines. The Earth's magnetic field looks like that of a dipole magnet where the field lines are coming out and going into the Earth near the poles. The auroral electrons are thus guided to the high latitude atmosphere. As they penetrate into the upper atmosphere, the chance of colliding with an atom or molecule increases the deeper they go. Once a collision takes place, the atom or molecule takes some of the energy of the energetic particle and stores it as internal energy while the electron goes on with a reduced speed. The process of storing energy in a molecule or atom is called "exciting" the atom. An excited atom or molecule can return to the non-excited state (ground state) by sending off a photon, i.e. by making light." ~ http://www.phy6.org/Education/waurora1.html "In Alaska, Canada, Norway, Finland or northern Russia, on a clear night, a greenish glow is often seen in the sky, known as the "Northern Lights." During magnetic storms, the glow may move southwards, and on occasion it can be seen in much of the US. It often appears as a glow on the horizon, like the glow preceding sunrise, and has therefore become known among scientists as "aurora borealis" ("aurora" for short), Latin for "northern dawn." A similar phenomenon is also seen in southern polar regions. To an observer, an aurora is a fascinating spectacle, constantly moving and changing. It usually consists of many near-vertical greenish rays, forming long arcs and curtains, which stretch like ribbons across the sky, often from horizon to horizon. The green light of the aurora has a precisely defined colour in the spectrum ("narrow spectral line"). Such precise colours are usually the signatures of the atoms which emit them... The green light of the aurora puzzled scientists for many years, since it fit no known element. It turned out to be produced by oxygen atoms, but under conditions that in our atmosphere only exist in the very rarefied upper levels. A red aurora, occasionally seen, arises at even greater heights and is also produced by electrons hitting oxygen."