A red light circle with a diameter of 360km flashed across the sky in Italy before disappearing in just a few milliseconds, possibly caused by electromagnetic pulses during a nearby storm.
Red circle in the sky over Italy on March 27. (Photo: Valter Binotto)
Natural photographer Valter Binotto swiftly captured the glow from the town of Possagno in northern Italy on March 27. In reality, the red circle, with a diameter of about 360km, did not appear directly above the town but rather in central Italy and the Adriatic Sea. The optical illusion made it look as if the circle was hovering above the town.
The circular light is described as “a glow and very low-frequency distortion from pulsed electric sources”, abbreviated as ELVE. ELVE is a form of stratospheric or mesospheric disturbance that is very rare, resulting from strong electrical effects during thunderstorms. The red circle is created when an electromagnetic pulse (EMP) is generated by lightning striking the ionosphere of the Earth, at altitudes of 80 to 644 km above the ground. Due to its extremely brief existence, ELVE is usually only observable through satellites orbiting the Earth. This phenomenon was discovered in 1990 thanks to cameras on NASA’s space shuttle. Binotto’s recent photo is likely the “clearest image of the phenomenon from the ground,” according to Spaceweather.com.
Binotto speculates that the ELVE was created by an EMP generated from a significant thunderstorm near Ancona, a city located about 280 km southeast of Possagno. Typically, lightning does not produce EMPs as they do not carry enough current. However, in this storm, a lightning strike was at least 10 times stronger than usual, generating electric shock waves that collided with the ionosphere. When electrons within the EMP interacted with the ionosphere, charged particles excited nitrogen atoms, emitting a red glow.
Since 2019, Binotto has photographed hundreds of ELVE events and various other short-lived luminous phenomena (LTE). According to the photographer, this is one of the largest structures he has ever observed.
