Provided you know a thing or two about shutter speeds and apertures, aurora borealis can be the subject of some truly mind-bendingly spectacular photographs. But even by the exceptionally high standards of images showcasing the Northern Lights, this is particularly special.
The photograph of a huge dragon-shaped aurora was shot in Iceland earlier this month by photographers Jingyi Zhang and Wang Zheng.
“This iconic display was so enthralling that the photographer's mother ran out to see it and was captured in the foreground,” NASA explains on the Astronomy Picture of the Day blog.
Aurora borealis, known as the Northern Lights when they occur in the Northern Hemisphere, aren’t just a pretty sight – they are the result of cosmic forces journeying across the Solar System. They are caused by solar particles spat out of the Sun’s corona, its upper atmosphere. When these solar winds reach Earth and smash into its magnetosphere (two to three days after they leave the Sun), they release their energy and excite oxygen and nitrogen in our upper atmosphere. The excitement causes ionization of the atmospheric molecules and the release of light photons. Oxygen produces green and yellow light, while nitrogen creates a red and blue light.
We tend to only see them at Earth’s most northerly and southerly points (the Southern Hemisphere's aurora is called the aurora australis) because the excited particles are pulled down by our planet’s magnetic field lines that gather at the pole.
As for that dragon shape, well, that's just down to some good luck. Though, it's not difficult to see why people once thought the aurora were the dances of an ancestral spirit or cosmic God.
Earth experiences more auroral activity during solar storms, where the Sun’s solar wind are especially plentiful. NASA's Picture of the Day blog notes that early February did not appear to have any sunspots, so numerous reports of aurora this month are “somewhat surprising".
