RocketSTEM Issue #5 - January 2014 | Page 26

An illustration of the structure of the magnetosphere which partially protects Earth from the Sun’s radiation. Graphic: Original image by NASA, Additional rendering by Aaron Kaase via Wikipedia.com In essence, the electrons from the solar wind attach themselves to the orbits of the Oxygen and Nitrogen atoms in our atmosphere and excite them; this gives rise to the colours. Aurora typically exhibit a prominent green colour, which the interaction with the molecular Oxygen. Atomic Oxygen often gives off a red glow and Nitrogen a pinky colour. The colour is actually the result of a photon of light being emitted from the exited molecule and then returning to what we call its ground state or lowest level of excitement. This takes place at higher altitudes normally way up in the Ionosphere. To best put yourself in a god place to view the Aurora, you need to travel into the polar regions, Alaska, 24 24 and Northern Canada; Northern Russia and in Europe places like Norway and Iceland are prime aurora hunting locations. Once you find yourself in these locations in winter you then have a front row seat for natures most fantastic natural firework display. As the Earth rotates around, your location will enter what we call the Auroral oval, this is an area of activity away from the pole of the Earth, here, when your locations moves round into this zone you should see, given good clear conditions various Aurora. Aurora comes in many different forms, from Arcs, to Ray’s, Curtains, and others. Some Aurora is quite faint, and a good dark site will be essential to see. Other bright Aurora at the time of more solar activity can easily be seen from cities. There are of course many legends associated with the lights. In fact people left a record of aurora from around 30,000 years ago in the late Pleistocene era in France where a painting by the Cro Magnon’s depicted it, and in 2500Bc the Chinese made Aurora records too. Hesiod of Greece one of the greatest poets ever to live wrote of “Blazing Skies” and “Dragons”, and Aristotle described the lights as a “Shining Cloud” Various cultures saw the Aurora as harbingers of doom, in Northern Europe for example the lights were considered a bad omen, and warned of illness and Plague. When red aurora was seen this was said to foretell of war and the red being the “blood of battle”. www.RocketSTEM.org