On September 7, 2017, an 8.1-magnitude earthquake struck off the southern coast of Mexico. Soon afterwards mysterious, green lights were seen in the sky.
The mysterious lights didn’t immediately have an explanation, but scientists say now the event was a result of Earthquake lights. It is a phenomenon so unusual that it has long considered to be a myth.
The first recorded sighting of Earthquake lights took place around 89 B.C. Over the centuries, there have been many reports of earthquake lights, both before and while the ground is shaking. The lights have many times been mistaken for birds, planes, or UFOs.
Italian priest and naturalist Ignazio Galli published in 1910 a first scientific description of Earthquake Lights (EQLs). In his book “Raccolta e classificazione dei fenomeni luminosi osservati nei terremoti” (Collection and Classification of luminous phenomena observed during earthquakes), he recognized four types: short-lasting (just a few seconds) and long-lasting (for minutes or hours) diffuse lights, flares, luminescent clouds and moving orbs of light.
According to scientists the lights are caused by electrical properties of certain rocks in specific settings and the lights can appear in many different shapes, forms, and colors.
On November 12, 1988, people reported a bright purple-pink globe of light along the St. Lawrence River in Quebec, 11 days before a powerful quake.
People also reported seeing a faint rainbow of light before the great 1906 quake in San Francisco and lights before the devastating 1811-12 New Madrid earthquakes in Missouri.
Not long ago, Earthquake light were observed during foreshocks and the main earthquake in L’Aquila, Italy, in 2009, and as flashes of blue lightning over Wellington, New Zealand, in 2016.
“These phenomena are well-documented because of so many security cameras running day and night now,” Friedemann Freund at NASA’s Ames Research Center said.
Freund explained that common forms of earthquake lights include bluish flames that appear to come out of the ground at ankle height; orbs of light called ball lightning that float in the air for tens of seconds or even minutes; and quick flashes of bright light that resemble regular lightning strikes, except they come out of the ground instead of the sky and can stretch up to 650 feet (200 meters).
The lights in Mexico sparked speculation online, with social media users suggesting a range of explanations, including thunderstorms, a solar phenomenon and even reflection from city lights. However, scientists now say they were indeed most likely Earthquake lights.