The sun is reaching the peak of its activity — it can cause more auroras and solar storms

The recent surge in solar activity has provided a unique opportunity for people worldwide to witness the magnificent display of the northern and southern lights. This stunning phenomenon was triggered by a powerful solar storm that had a significant impact on Earth's magnetic field.

As the sun approaches the peak of its 11-year activity cycle, we can expect more eruptions of particles, which play a crucial role in creating both the beautiful auroras and the potentially destructive geomagnetic storms. Typically, the northern and southern lights are confined to high and low latitudes. However, during periods of strong solar events, they can be observed at lower latitudes as well.

So how exactly do these phenomena occur? High-energy particles emitted by the sun travel towards Earth, guided by the solar magnetic field. Through a process known as reconnection, these particles are transferred to Earth's magnetic field. They then race down the magnetic field lines until they collide with neutral atmospheric particles like oxygen, hydrogen, or nitrogen. In this collision, some of the energy is lost, resulting in the heating of the local environment.

Interestingly, the atmospheric particles release a portion of the excess energy in the form of visible light. The specific elements involved determine the wavelengths and colors emitted, giving rise to the vibrant hues of the auroras. Nitrogen contributes to the blues and purples, while oxygen produces the greens and reds. This process primarily occurs in regions near the Arctic circle or Antarctica due to the shape of Earth's magnetic field, resembling that of a bar magnet.

What allowed the auroras to be seen much further south in the northern hemisphere? To understand this, envision the common school experiment where iron filings align with a magnetic field. Similarly, Earth's magnetic field is always present but can be compressed and released in response to solar activity. This can be compared to two half-inflated balloons pressed against each other. As the pressure from solar activity increases, the relevant magnetic field lines are pushed closer to the equator, enabling auroras to be visible at lower latitudes.

While auroras bring awe-inspiring beauty, they also pose some potential problems related to electrical currents generated by the shifting magnetic fields. Infrastructure such as power lines, train tracks, and underground pipelines are particularly vulnerable to induced currents. Strong magnetic storms, like the ones observed on May 10 and 11, raise concerns as they have the potential to cause damages. Power stations have some safeguards in place, but metallic pipelines, for instance, can experience slow erosion over time due to the passing electrical currents, leading to significant impacts that are challenging to detect.

Space-based systems face additional challenges, as satellites have limited grounding and are susceptible to electrical surges that can destroy instruments and disrupt communications. Changes in Earth's magnetic field can also impact the accuracy of GPS-style location systems, causing delays in signal transmission. Furthermore, satellite internet bandwidth speed and the planet's radiation belts can be influenced, affecting HF radio used by aircraft and even ozone concentrations.

Auroras extend beyond our planet, and their presence on other celestial bodies provides valuable insights into their magnetic fields. One fascinating apparatus, known as a "planeterella," offers a simulated experience of auroras. These devices, including budget versions developed by researchers, involve placing a magnetic sphere representative of Earth in a vacuum chamber and simulating solar wind by directing electrons towards the sphere. By altering magnetic field strength and distances, observational studies on how auroras change can be conducted.

In addition to being a natural marvel, geomagnetic storms serve as crucial reminders to enhance protective measures against potential damage from future events. With every strong solar event, we gain valuable knowledge that aids in the improvement and preparation for safeguarding our infrastructure and technological systems.