It’s not every day you look up and see the universe playing alphabet games. On November 22, Alaska’s sky offered something truly out of the ordinary: a glowing green “E” shimmering against the dark canvas of the early morning. For aurora hunter Todd Salat, this was a jaw-dropper.
“It came up from the northwest, and I thought, ‘Whoa!’ It really looked like the letter E,” Salat shared with Spaceweather.com. Over the next few minutes, the letter morphed and flipped before vanishing entirely.
But what made this celestial event extraordinary wasn’t just the shape—it was the rare phenomenon behind it: black auroras, or anti-auroras. Unlike the usual vibrant greens, reds, and purples that streak across polar skies, black auroras create dark voids that seem to suck the light right out of the display.
What Exactly Are Black Auroras?
Think of black auroras as the cosmic introverts in a room full of extroverts. While traditional auroras are caused by charged particles from the sun energizing atmospheric gases and creating light, black auroras work in reverse. These dark gaps form when electrons are ejected back into space, creating “holes” in the glowing spectacle.
The result? A stunning, almost eerie contrast as luminous shapes like the Alaskan “E” emerge against the darkness. According to the European Space Agency (ESA), black auroras occur in small, localized regions of the ionosphere where positively charged electric structures repel electrons.
Science Behind the Spectacle
Scientists first started decoding black auroras in the late 1990s, but it wasn’t until 2001 that a breakthrough came. The ESA’s Cluster satellites observed the phenomenon directly, revealing how ionospheric cavities formed when auroras depleted plasma in Earth’s upper atmosphere.
Fast-forward to 2015, and researchers pieced together even more of the puzzle. Using over a decade of satellite data, they linked black auroras to disruptions in Earth’s magnetosphere caused by solar storms. Essentially, when the magnetosphere shifts under stress, these dark, swirling patches can form within traditional auroras.
But here’s the catch—black auroras are fleeting, lasting only 10 to 20 minutes, and require a perfect storm of conditions to appear.
Why Now?
If you’ve been paying attention to auroras lately, you might’ve noticed they’ve been popping up more frequently and in places they usually don’t. That’s because we’re nearing the solar maximum, the peak of the sun’s 11-year sunspot cycle. Increased solar activity means more charged particles hitting Earth’s atmosphere, leading to brighter and more frequent auroras—and yes, even the rare black ones.
For Alaskans and aurora enthusiasts, this means the sky isn’t just the limit; it’s a canvas for nature’s unpredictable art. With solar activity expected to stay high over the next few years, now’s the time to keep your eyes peeled for more celestial surprises.
If you’re lucky, maybe you’ll catch another letter or two. Cosmic Scrabble, anyone?
