- A recent interstellar event caused excitement due to a never-before-seen phenomenon on the sun’s surface.
- A “prominence” separated from the sun, swirled around its north pole, and promptly disappeared.
- This raises several questions, according to an expert who spoke with Popular Mechanics about the rare event.
On February 2, material from the sun separated from the star and got sucked up into a polar vortex. The never-before-seen phenomenon was visible in a clip Tamitha Skov, a space weather physicist, shared on Twitter:
More accurately, a “prominence”—an arc of dense gas that spouts out from the sun’s surface due to strong magnetic field forces—broke away from the sun and swirled around its north pole in a rare occurrence. Rare, not because of the separation, but because of the subsequent wobbly dance the prominence engaged in before disappearing from sight.
One of the reasons this new data is exciting is because of the level of detail we were able to see when the event took place, explains R.T. James McAteer, an associate professor of astronomy at New Mexico State University.
But what exactly is a polar vortex on the sun’s surface? And what are the implications for us here on Earth?
What Happens When the Sun Reverses Its Magnetic Poles?
Every 11 years, at the peak of the solar cycle (known as the “solar maximum,” in which the sun has the most number of sunspots), the sun reverses its magnetic poles. The last time this happened was around 2013 during Solar Cycle 24, when the sun’s north and south poles flipped their polarities.
The result of such a massive shift in polarity is wild space weather that includes solar flares, solar winds traveling at high speeds, and coronal mass ejections. When material breaks away from the sun—as in the case of solar flares, which are comprised of energy and plasma—we typically call it a “polar crown eruption,” which McAteer says is fairly common, especially around this period of the solar cycle.
“When the material leaves the sun, it can sometimes be detected as a coronal mass ejection (CME),” McAteer tells Popular Mechanics. He notes that the cause of polar vortexes on the sun remains unknown.
✅ Know Your Terms:
A solar flare is the tipping point of intense energy that bursts from the sun, releasing radiation and tons of magnetic energy. How often solar flares occur is closely tied to the sun’s 11-year cycle.
Think of solar winds as the steam that billows out of a kettle when it has finally reached its boiling point. Like the boiling water in the kettle, solar plasma gets so hot that not even the sun’s gravity–which is about 28 times stronger than the gravity here on Earth–is able to keep it contained. The plasma follows the sun’s magnetic field waves, which form into a massive spinning swirl caused by the sun’s rotation, resulting in solar winds.
Coronal mass ejections (CMEs) are caused by clouds of energy and magnetized plasma erupting into space. CMEs are similar to solar flares in that they are both characterized by bursts of high-intensity radiation, but where solar flares travel at the speed of light, CMEs however, travel much more slowly by comparison. For example, some solar flares can reach Earth within minutes, while the fastest CMEs that shoot out toward Earth can take 15+ hours to reach us.
“Some scientists see that 55-degree latitude as a key boundary of overlapping zones, like magnetic bands. If this is real, a solar polar vortex could be analogous to the polar vortexes we find on Earth,” McAteer says. The 55-degree latitudes are hotbeds of activity that see solar eruptions and increased sunspots on the massive star’s surface once every solar cycle.
Then, the unknown becomes how the magnetic field interacts with the rest of the sun’s interior and atmosphere. “That’s where the fun part of the scientific discovery lies,” says McAteer.
And while we’re talking about polar vortexes on the sun, it’s important to note that they occur on Earth, too. However, unlike polar vortexes on the sun, Earth-bound polar vortexes are cold.
Our planet’s polar vortexes are characterized by a combination of low pressure and cold air. According to the National Oceanic and Atmospheric Administration (NOAA), polar vortexes on Earth typically only pose a threat to us when temperatures get near or below freezing, or when a polar vortex expands and pushes icy Arctic air into climates that don’t usually get freezing weather.
What Causes Polar Vortexes on the Sun?
The belief among some in the scientific community is that the reversal in the sun’s polarity is connected with the star’s magnetic field, possibly acting as the catalyst for polar vortexes (like the one that caused the solar flare ejection in early February), Scott McIntosh, deputy director of the National Center for Atmospheric Research tells NPR.
This chain-link reaction then “propagates through the whole solar system,” McIntosh says.
The bubbling plasma loop that launched itself away from the sun appeared to “snap back down and then [rotate] around the sun,” McAteer says. This still qualifies as a prominence, which is also sometimes called a “filament.”
“When the feature [a prominence] appears dark on the sun’s disc, it usually gets referred to as a filament. When it appears above the limb of the sun, it gets referred to as a prominence,” McAteer explains. “It’s the same physical feature.”
The Takeaway
The sun is currently barreling toward its maximum, the period within its cycle characterized by the highest amount of solar activity as well as the largest number of sunspots, and is expected to reach it in the summer of 2025. So, what does all of this mean for us earthlings? According to McIntosh, not much.
This ebb and flow of polarity and the shift in magnetism on the sun may cause similar events in the future, but they’re nothing we need to worry about.
