A skywatcher in the U.S. shared a video showing a rare and newly discovered atmospheric phenomenon in the sky known as a Green Ghost. According to experts, Green Ghosts tend to emerge right after another rare atmospheric event appears in the sky.
As its name suggests, a Green Ghost appears as a greenish emission in the sky. Based on observations, Green Ghosts usually appear over sprites, which are jellyfish-shaped red-colored electrical discharges. They often appear on top of thunderclouds at high altitudes.
Discovery of Green Ghosts
Green Ghosts were first documented and discovered a little over a year ago on May 25, 2019, by a storm chaser known as Hank Schyma, also known as Pecos Hank. According to Schyma, he spotted the rare phenomenon while he was watching sprites over thunderclouds in Oklahoma, SpaceWeather.com reported.
At first, scientists thought that the greenish hue that appeared in Schyma's videos were the result of his camera's sensors. However, after Schyma's fellow storm chaser Paul M. Smith captured high-resolution images of Green Ghosts, experts agreed that they were a new type of cosmic phenomenon.
Spotting Green Ghosts in The Sky
Almost a year after their discovery, a skywatcher in New Mexico spotted new sets of Green Ghosts. Similar to previous observations, the Green Ghost emerged following the appearance of sprites. Sky gazer Thomas Ashcraft shared a video of one of his rare Green Ghost sightings through Vimeo.
"In the past week I've captured two Green Ghosts over west Texas that were generated by strong peak current lightning strokes," he said, according to SpaceWeather.com. "The one on May 25th registered 118 kAmperes on the National Lightning Detection Network and saturated VLF lightning sensors as far away as Great Britain and Germany. As far as I know there are no scientific journal articles regarding this new phenomenon and a handful of citizen scientists are leading the way."
Possible Explanation Behind Green Ghosts
Currently, not much is known about the nature of Green Ghosts. However, experts believe that its greenish color could be a clue to its origins and formation. This color in the sky can be commonly seen in auroras and airglows, which are atmospheric phenomena that glow due to the presence of active oxygen atoms.
In most cases, these atmospheric phenomena are caused by cosmic rays and solar particles interacting with the oxygen atoms. The same process could also trigger the formation of Green Ghosts. Since sprites tend to appear at high altitudes of about 90 kilometers from the surface, their electrical charges could excite the oxygen atoms in the atmosphere, creating a greenish glow around them.