Whether you’re talking about auroras, the beautiful glowing lights known as STEVE, or green-hued and mysterious “ghosts,” our sky is packed with strange and alluring phenomena. While we know what causes auroras and even have an idea of what causes STEVE, the origins of mysterious “ghosts” that sometimes appear in the sky during intense storms have alluded scientists. But now, a new study may finally have some answers.
Likewise dubbed a “ghost” by Texan rock singer Hank Schyma when he captured a photo of one of these mysterious events back in 2019 (via EL PAÍS), these ghostly images are actually known as Green emissions from excited Oxygen in Sprite Tops, or GHOST. And according to a new study, they’re caused by the presence of metals entering the atmosphere.
These ghosts are just one part of a group that scientists label transient luminous phenomena. The first of this grouping of optical events was originally observed as far back as 1989, during a hurricane in the United States.
Because of how fleeting and elusive they are, scientist Dave Sentman labeled them sprites. However, others have been observed and named similarly, with Elves appearing as ring-like glows, while trolls are purple jets of light in the sky. Ghosts, however, are even rarer, sometimes appearing on occasion above the sprites, and they weren’t even recorded as being observed until Shyma took his photograph.
To discover the origin of the ghosts, though, scientists María Passas Varo with the Spanish Research Council’s Andalusia Institute of Astrophysics in Granada, worked with her colleague, Justo Sanchez del Rio, to use an instrument they had designed that could analyze colorful, fleeting electrical discharges high above storm clouds.
When they heard of the mysterious green ghosts that Shcyma had observed, they began to study the phenomenon, looking for details about its origin. Eventually, they discovered that most of the ghost was made of iron, with only a tiny amount of oxygen. These new findings, they believe, could explain why the ghosts appear to be so rare and infrequent.
The researchers believe that the iron needed to cause the appearance of these green ghosts comes when meteors burn up in Earth’s atmosphere, leaving traces of metal behind that become suspended in the atmosphere. When the electrical current moves through it, causing a sprite, it forms the mysterious ghostly figure above it, too.
