Unexpectedly bright aurora illuminated the British skies in 2024
John Hayward/SWNS
If you have an interest in the Aurora Borealis, you’re in for a treat. Last year was a spectacular one, as auroras dazzled observers worldwide, even being visible far south with remarkable brightness. With a peak in solar activity, more stunning displays are anticipated, potentially leading to extreme geomagnetic storms. To grasp the phenomena behind these celestial light shows, one must look to the fiery depths of the sun.
Comprehending the sun’s workings is crucial to explaining various phenomena occurring in the Earth’s atmosphere and the solar system, not limited to auroras. Space Weather Physicist Tamitha Skov has been instrumental in enhancing our understanding of the sun’s mysterious operations through auroras and space weather forecasts on television and social media.
Skov discussed with New Scientist the reasons for the extreme auroras we’re witnessing and the increased frequency of space weather events. She noted that high-energy particles emitted by the sun present real risks to astronauts and spacecraft venturing beyond the protections of Earth’s magnetosphere. Scientists are continually searching for better prediction methods for these potential hazards. “Good sailors know to heed the weather; the same applies to space,” she remarked.
Alex Wilkins: What inspired you to study the sun and space weather?
Tamitha Skov: The sun is an incredibly captivating entity, maintaining its integrity for billions of years. However, my primary fascination comes from our connection to our planet. As a longtime admirer of Carl Sagan, I recall his words: “We are all made of star stuff,” which frames my curiosity about our origins and the elements that compose us.
Initially, I rekindled my interest in solar phenomena from a physical perspective, which shifted my focus to space weather. At that time, we were only beginning to understand that solar activity impacts Earth, making this area of research incredibly engaging. I’ve become absorbed in exploring the unseen electric and magnetic fields that influence the dynamics of the sun and the universe.
Recently, we’ve observed a rise in auroras, largely due to heightened solar activity. What’s happening with the sun?
We are experiencing a solar cycle. The sun goes through several cycles, with the dominant one being the Schwabe cycle, which lasts about eleven years. During the low phase, the sun is relatively quiet, resembling a hibernating bear before awakening to produce an array of solar activity.
This phenomenon is characterized by the sun’s magnetic field reversing. Imagine a lava lamp—when it’s off, the liquid remains still, showcasing a calm and orderly state. However, once activated, bubbles rise, creating a chaotic fusion of materials. This defines our sun’s state during its peak activity, when magnetic fields become disconnected, resulting in massive energy releases. Such instability breeds numerous solar eruptions as the sun reorganizes its magnetic field.
Tamitha Skov notes the recent surge in solar activity marks a return to normalcy
ng images/aramie
Are we witnessing a different phenomenon compared to prior solar cycles, given the auroras are now appearing much farther south?
To a degree, yes. It seems like various factors have come together to create an intriguing moment in time. After two solar cycles characterized by quiet activity and advancements in technology since the 1990s, we now have social media to share auroral experiences globally. Previously, during significant storms, there were no sensitive cameras available to capture these events.
In the current solar cycle, we are hitting G4 and G5 levels of storms—among the most extreme—and the availability of modern cameras enhances our ability to witness auroras, even from less vibrant displays. This may create an illusion that auroras have never appeared in the past, but science tells us they have been frequent, just not documented.
Furthermore, the Earth’s magnetic field is changing, altering the position of the auroras as particles penetrate deeper due to its weakening, which naturally slows the stirring in the Earth’s core.
Does the increased auroral activity indicate the sun is at its peak in this solar cycle?
As we reach the climax of this solar cycle, the observations lead many to believe the sun is behaving unusually. However, this notion simplifies what we’ve come to know; the previous cycles (24 and 23) were indeed the anomalies. Currently, our sun is displaying a behavior consistent with its historical patterns.
We’re now experiencing what constitutes an average cycle, not particularly intense. Previous cycles have exhibited even more activity than this one, making the notion of a prolonged inactive phase the true anomaly.
How concerned should we be about solar eruptions surpassing the intensity of the Carrington event of 1859, which resulted in widespread disruptions?
We’ve enhanced our knowledge about these events and their impacts on our infrastructure, accompanied by improved warning systems. The power grid remains a significant concern. During such storms, the Earth’s magnetic field generates strong fluctuations, creating currents similar to traffic jams in highways. When these currents encounter grounded power lines, it can overload systems that were not designed for such energy spikes.
To mitigate risks during storms, we can temporarily disconnect transformers from the ground. While this tactic carries potential dangers, it can be safer than leaving the grid fully connected. Some of these methods were validated during a G5 storm in May 2024, yielding promising results despite minor issues.
Our attention is also shifting towards GPS and navigation systems, particularly after storms during planting season last October created headaches for precision agriculture, notably impacting peanut farmers reliant on accurate geographical data. Rapidly deploying new technologies becomes crucial to address impending challenges.
Solar activity at its peak leads to the release of charged particles
NASA’s Goddard Space Flight Center/SDO
These challenges apply to Earth, but how do they differ for spacecraft and astronauts bound for the moon or Mars?
Our atmosphere provides crucial protection that is absent on other celestial bodies. When viewing photos of the sun from the ground, one sees merely a bright orb because our atmosphere absorbs harmful radiant energy. This energy can cause radiation sickness if it reaches the surface. However, on a lunar body devoid of atmosphere, astronauts must shield themselves from radiation storms—high-energy particles unleashed from the sun. Researchers are exploring protective measures, such as constructing deep lunar bases and creating artificial magnetic fields.
Astronauts are already exposed to radiation during low Earth orbit missions, but exposure increases significantly on the moon.
Space weather has been remarkably fortunate historically. During the Apollo era in 1972, there was a severe particle radiation storm that could have been fatal for astronauts on the moon. Prolonged exposure to such radiation might have been lethal while confined in spacesuits. If that incident had unfolded differently, it would have dramatically altered the course of space exploration. Even today, these threats often go unnoticed.
While Mars possesses a weak atmosphere, radiation storms can still reach its surface. Thus, astronauts can’t just hide behind surface features; instead, they must live underground, introducing various complications to missions.
Source: www.newscientist.com
