At a scientific conference in Vienna last week researchers brought forth some tantalizing new details about a odd form of lightning you’ve probably never heard of: dark lightning. Dark lighting is a largely-invisible burst of energy that floods the sky with gamma rays and hurls antimatter into space, says NASA. It sticks around for just a few microseconds, but if you do happen to see it, dark lighting shines with a faint purple glow, says Discovery News. The bursts of gamma rays affect the region often occupied by cruising airliners, but the radiation dose is pretty low: “similar to going to the doctor’s office and getting a CT scan.” So, not particularly dangerous.
Dark lightning was first discovered in 1994, and is just one of many odd and usual forms of lightning that have puzzled researchers in the past few decades.
Regular lightning, which you’ll find arcing down from a thundercloud, is dazzling enough, especially when watched at high speed.
But really, such cloud-to-ground lightning can’t hold a candle to some of the rarer breeds of electrical discharges.
Volcanic lightning, for instance, can be produced when ice crystals in the volcanic plume collide.
Red sprites are a stunning form of lightning that was first discovered in the late 1980s. Red sprites eluded us for so long because they shoot not between the Earth and a cloud but from the top of a cloud up toward space, sometimes stretching more than 30 miles.
For more information, John Dwyer, the scientist behind the new research on dark lightning, has a detailed lecture on weird lightning that you can watch.
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