Extremely rare black anti-auroras create an E-shaped swirl of light in this recent image above Alaska.
A strange E-shaped aurora was recently photographed over Alaska. This unusual light show is caused by the rare black aurora, also known as anti-aurora, a phenomenon that ejects charged particles from the Sun out of Earth’s atmosphere and into space. Live Science reported on December 4.
Aurora hunter Todd Salat discovered an unusual aurora display on November 22 at a location in south-central Alaska at about 4 a.m. local time. The glowing E appeared to appear suddenly and lasted several minutes while morphing through several shapes, all of which contained dark patches absent from most auroras.
“It came from the northwest and I just went wow. It looked like the letter E. Within a few minutes, it transformed and looked like some legged insect in mid-air,” Salat said.
Anti-aurora is an unusual phenomenon that creates many circular dark patches that look as if they have been bitten. As the name suggests, the anti-aurora is essentially the opposite of the aurora. They prevent the gas from releasing energy in the form of light. The result is dark circles, curls or drops interrupted by vibrant colors, according to the European Space Agency (ESA).
Auroras are triggered when high-energy particles from the Sun, mainly electrons, penetrate the Earth’s magnetic field or magnetosphere and super-heated gas molecules in the upper atmosphere. Excited molecules release energy in the form of light, coalescing into soft, elongated bands winding across the sky. Their color varies widely depending on the element being excited and the location in the atmosphere. Auroras usually only occur near the poles, where the Earth’s magnetic field is weakest. But they are especially prominent and common now due to increased solar activity during the peak phase, the peak of the 11-year cycle.
However, anti-auroras disrupt the auroral formation process by causing the gas to lose charged particles. “The black aurora is not really an aurora. It’s a lack of auroral activity where electrons are sucked out of the ionosphere,” said Göran Marklund, a plasma physicist at the Royal Swedish Institute of Technology in Stockholm. , said.
Anti-auroras were first identified in the late 1990s. But in 2001, scientists discovered their mechanism of action when four NASA Cluster satellites flew through space above the anti-aurora. The activity revealed tiny gaps in the upper atmosphere where electrons are ejected back into space. A 2015 study using more than a decade of data from the Cluster mission found that these slits form when auroras lose plasma, creating holes in the upper atmosphere,
Anti-aurora can occur during the Northern Lights and Southern Lights, usually only lasting about 10 – 20 minutes. Experts predict that aurora activity will continue to be strong in the next few years.