The Northern Lights (named aurora borealis by Galileo in 1619 after the Roman god of dawn and the Ancient Greek for northern wind) are caused by the interaction of the solar winds (travelling at over 400 miles per second) with the earth’s magnetosphere, which is why most of the light is produced 60 miles and upto 600 miles above the ground.
The brightest known auroras were in 1859 when the New York Times reported that in Boston you could read a newspaper at one o’clock in the morning, and enough electricity was produced to power telegraph services without (and better than) the usual batteries.
Most displays are green because of high concentrations of atomic oxygen and the eye’s higher sensitivity to green, but red, pink, blue, violet and yellow are also visible.
Photographing auroras is extremely difficult, not least because the results are unpredictable, and it takes stratospheric levels of technology, expert skill and dedication to achieve the high quality images we are privileged to be using. They have been taken by Andrew Machon after years of dedication and investment in cutting edge photographic equipment - as well as months spent in the Arctic Circle.