On March 23, an unexpected coronal mass ejection (CME) occurred from a gigantic spot on the Sun that is twenty-three times larger than our planet. A huge mass of plasma blasted through space extremely quickly and collided with Earth’s magnetic field, creating the strongest geomagnetic storm in six years and causing spectacular auroras around the world.

what is known

Glitter wasn’t the only surprise. The STEVE phenomenon, also known as “strong thermal radiation velocity increase”, is a rare atmospheric effect that was officially discovered in 2016. During STEVE, a long, thick strip of light – usually white, purple or green – hangs in the sky for up to an hour. Although this phenomenon is very similar to the aurora borealis and often occurs simultaneously, STEVE is not actually an aurora borealis.

The phenomenon has been photographed in the USA in South Dakota, Washington State, Idaho, Montana (twice), and Scotland.

Vibrant purple STEVE cuts through the night sky over Badlands National Park in South Dakota / Photo: Evan Ludes/Framed By Nature

STEVE via Washington / Photo: Rocky Reibell

STEVE via Washington / Photo: Rocky Reibell

STEVE via Washington / Photo: Rocky Reibell

What is the difference between STEVE and aurora borealis?

• during the aurora borealis high-energy particles from solar storms and solar wind break the planet’s magnetic field or magnetosphere and activate gas molecules in the upper atmosphere. This creates vortices of light that disappear and appear over time.
• But STEVE isn’t caused by high-energy particles and can occur much further from Earth’s poles than auroras, although scientists still don’t know why. STEVE causes by a stream of hot plasma or ionized gasIt breaks through the Earth’s magnetosphere due to magnetic disturbances during solar storms and enters the ionosphere. This plasma moves at about 21,400 kilometers per hour, which creates friction with the surrounding air and stimulates the molecules to glow like the aurora borealis. But the continuous flow of plasma causes a stagnant visual phenomenon for the observer that can be compared to the dancing lights of the aurora borealis.

STEVE may also be accompanied by striped green lights in the sky that flash for about 30 seconds and then disappear. Experts believe they formed in a manner similar to the aurora borealis, but the nature of the striped lights is not fully understood.