Science

Polar Lights: A Mirage Concealing the Sun’s Destructive Activities

Though the polar lights are beautiful and mesmerizing, they conceal the truth about solar storms and the chaotic, destructive nature of the Sun.

Reading Time: 5 minutes

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By Jocelyn Yu

Throughout history, various groups of people have marveled at the polar lights each time the swathes of colorful blaze appear in the night skies. Some, such as the Inuits, believed these lights were their deceased relatives’ way of communicating with them. On the other hand, Native American tribes believed these lights were a bad omen of things to come, especially when auroras expressed red hues, which were thought to represent bloodshed. With modern technologies, however, scientists have found the actual explanation for polar lights: the Sun.

Polar lights, also known as auroras, are naturally occurring displays of light that can be seen at night in the Arctic and Antarctic circles, denoted at 66.5 degrees above and below the equator, respectively. These lights typically exhibit a wide range of colors, including blue, green, red, and pink, all slowly flowing through the night sky in mesmerizing patterns. In the North, these polar lights are known as aurora borealis, while the ones in the South are known as aurora australis.   

Though we typically perceive the Sun as a stable object providing Earth with heat and sunlight, the Sun is actually in constant flux, causing it to continuously eject small energetic particles of mass toward us. The only reason why these particles’ effects appear negligible to us is because of Earth’s powerful magnetic field, which shields us from their ejections. However, when the Sun experiences a solar storm, an event where large amounts of energy and particles are emitted, the Sun’s output exceeds the normal amount. These solar storms may occur only a few times a month but can also occur very often, up to multiple times a day. The type of solar storm that causes polar lights is known as a coronal mass ejection (CME) and is characterized by the Sun emitting a large cloud of solar plasma consisting of electrons and protons. A CME can reach millions of kilometers per hour as it collides with the Earth. Fortunately, the Earth’s powerful magnetic field usually manages to shield us from these ejections and turn them into polar lights.

Earth’s magnetic field creates areas shaped as two large auroral ovals above the poles, depicting where auroras are likely to occur. Next, the magnetic forces essentially pull these solar particles towards the poles, where they react with gas particles within our atmosphere to form the polar lights. This is also why aurora lights are very common—as the Sun ejects particles, the magnetic fields guide the particles toward the poles and create auroras.

These lights are formed specifically from charged particles such as electrons and protons. As they collide with atmospheric elements, atoms become excited and gain energy, which is then released in the form of light as the particles return to their natural state. The color of the released light corresponds with the energy gained by the atoms, with the lowest energy exhibiting red light and the highest energy exhibiting violet light. When these particles react with oxygen, the auroras have a green color, and when they react with nitrogen, purple, blue, and pink hues appear in the polar lights. The rarest color is red, which only occurs when the solar particles are extremely energized, allowing them to react with oxygen at very high altitudes. Though this may seem contradictory to red light being associated with lower energy, higher altitude oxygen requires more energy to become excited due to the fact that it is less dense than lower atmospheric oxygen. This results in just enough energy for a reddish hue.

However, even though auroras are an extremely captivating phenomenon, they shroud the dangerous and destructive activities of our Sun. Typically, the presence of auroras does not pose a risk to living organisms, but the electromagnetic energy released through the collision of solar particles with the atmosphere can lead to detrimental effects on nearby infrastructure and technology. More specifically, electrical components and space satellites are particularly vulnerable to the effects of electromagnetic radiation, resulting in interference with communications and signals. This can be very inconvenient for GPS signals as well as military operations that require communication services. Entire satellites can be rendered disabled as the electromagnetic radiation messes with their internal systems, and planes can lose communication with other planes, slowing air traffic.

To better understand this aurora interference, also known as a geomagnetic storm, we must understand the strength of the Sun’s solar storms. Though most solar storms aren’t threatening to Earth, the Sun does experience a process known as a solar maximum, which occurs approximately every 11 years. This happens when the Sun’s magnetic field gets tangled as it rotates for long periods, eventually swapping its North and South poles, leading to peak solar activity that can last for multiple years. As a result, the effect of the Sun’s solar storms becomes magnified, causing more energy and particles to slam into the Earth’s magnetic field. This leads to more electromagnetic radiation being released, and thus, larger power and communication blackouts. Incidences of solar maximum also increase the potential to directly penetrate the Earth’s magnetic field without being redirected to the poles, leading to more areas being affected by this geomagnetic interference. Thus, though auroras themselves don’t pose a risk, they are a spectacle that diverts our attention from the chaotic processes of the Sun.

The effect of aurora interference is amplified by the fact that the contemporary world relies heavily on technology. In 1859, the largest solar storm ever recorded was measured. This storm, known as the Carrington Event, wasn’t too devastating at the time. In today’s world, however, scientists predict that a geomagnetic storm of the same magnitude would cause extensive damage to our technological infrastructure, including electrical grids and satellite-based technology.

The next solar maximum will come much earlier than expected and is currently predicted to begin near the end of 2023—essentially right now. Scientists have predicted that this next solar storm will be particularly disruptive by measuring sunspots and solar activity. Simply put, a higher number of sunspots is correlated with a solar maximum. Though we may be getting larger and more beautiful auroras in the years to come, they do not come without risks and dangers.

Fortunately, humans are not completely defenseless when it comes to shielding themselves from solar storms. With new space technology, we can track solar activity much better than in previous decades, allowing us to prepare for blackouts and communication outages caused by solar electromagnetic radiation. New satellites are also equipped with shielding around sensitive electronics to block particles from the Sun and help mitigate damage. These shields are typically made of aluminum, an extremely effective reflector of electromagnetic radiation. Capacitors are present on Earth in many areas, allowing for the absorption of energy spikes caused by the Sun.

The captivating auroras found in the North and South poles are intimately linked to the activities of our Sun. However, hidden behind the ethereal flow of colors is the turbulent behavior of solar storms. As we near the next solar maximum, if you have the chance to witness auroras in the night sky, remember that these beautiful light displays are the echoes of solar storms hidden from the casual observer.