Geomagnetic storms, also known as space weather disturbances, are temporary disturbances of the Earth’s magnetosphere caused by solar activity. These events can have significant impacts on various technological systems and even on human health. Understanding the causes, effects, and potential mitigation strategies for geomagnetic storms is crucial in our increasingly technologically reliant world. The primary driver of geomagnetic storms is the Sun. Coronal mass ejections (CMEs), large expulsions of plasma and magnetic field from the solar corona, are often the cause. These CMEs travel through space and can, if directed towards Earth, interact with our planet’s magnetosphere. Solar flares, sudden releases of energy from the Sun’s surface, can also contribute to geomagnetic storms, although their impact is usually less significant than CMEs. When a CME reaches Earth, it interacts with the magnetosphere, compressing and distorting it. This interaction can transfer energy into the magnetosphere, leading to increased electric currents in the ionosphere and magnetosphere. These currents create their own magnetic fields, which interact with Earth’s magnetic field, causing rapid and irregular fluctuations. These fluctuations are the hallmark of a geomagnetic storm. The effects of geomagnetic storms are wide-ranging. One of the most significant impacts is on power grids. Geomagnetically induced currents (GICs) can flow through power lines and transformers, potentially overloading them and causing blackouts. The 1989 Quebec blackout, triggered by a geomagnetic storm, is a stark reminder of this vulnerability. Communication systems are also susceptible. Geomagnetic storms can disrupt radio communications, particularly high-frequency (HF) radio, which is used by airlines, ships, and amateur radio operators. Satellite communications can also be affected, potentially leading to signal loss or degradation. Navigation systems like GPS can experience errors due to ionospheric disturbances caused by geomagnetic storms. Pipelines can also be affected by GICs, which can accelerate corrosion. This can lead to leaks and environmental damage. While less documented, some studies suggest potential impacts of geomagnetic storms on human health. Some research has linked geomagnetic activity to increased risk of heart attacks and strokes, although the mechanisms behind these effects are not fully understood. Pilots and airline passengers may also be exposed to higher levels of radiation during geomagnetic storms. Predicting geomagnetic storms is a complex and challenging task. Space weather agencies around the world, such as the Space Weather Prediction Center (SWPC) in the United States, monitor the Sun for signs of impending geomagnetic activity. They use satellite observations of solar flares and CMEs to forecast the likelihood and severity of geomagnetic storms. Mitigation strategies are essential to reduce the vulnerability of infrastructure to geomagnetic storms. For power grids, these strategies include implementing GIC-blocking devices in transformers, improving grid monitoring and control systems, and developing emergency operating procedures. For communication systems, strategies include using more resilient communication frequencies and developing backup communication systems. Early warning systems can provide valuable time for operators to take preventative measures. Continued research and development are crucial for improving our understanding and prediction of geomagnetic storms. This includes improving our ability to forecast solar activity, developing more accurate models of the magnetosphere, and understanding the effects of geomagnetic storms on various systems. Investing in these areas will help us better protect our infrastructure and society from the potentially disruptive effects of these space weather events.