An aurora is a natural light display in the night sky, particularly in the polar regions, caused by the collision of charged particles directed by the Earth’s magnetic field. The aurora most often occurs near the equinoxes.
Aurora Borealis season in northern polar latitudes (Alaska, northern Canada, Greenland, Iceland, Norway, Sweden, Finland and Siberia) runs from August-thru-April. Its southern counterpart, the aurora australis or the southern lights, has similar properties, and is visible from high southern latitudes in Antarctica, South America or Australasia.
Green is the most common color in all auroras. Behind it is pink, a mixture of light green and red and lastly pure blue. Oxygen emissions lead to green or brownish-red, depending on the amount of energy absorbed. Nitrogen emissions lead to blue or red color. Blue if the atom regains an electron after it has been ionized. Red, if returning to ground.
In northern latitudes, the effect is known as the aurora borealis or the northern lights, named after the Roman Goddess of dawn, Aurora and the Greek name for the north wind, Boreas, by Pierre Gassendi in 1621.
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