Why auroras?
You might have seen it on social media: auroras were visible worldwide on the nights of May 10 and 11. This phenomenon was caused by a solar storm, the most intense since 2003, that hit our planet. According to the National Oceanic and Atmospheric Administration (NOAA), this geomagnetic storm reached level 5, the highest on their scale.
Solar storms are triggered by eruptions of charged particles from the Sun. When these particles reach Earth, they interact with the planet's magnetic field, creating colorful lights in the night sky. These particles are guided by the magnetic field lines toward the poles, where they collide with atmospheric molecules, producing green, red, blue, and purple hues.
Why Réunion and not Mauritius?
Despite common belief, southern auroras were visible in the Mauritian sky, though faintly. Although Mauritius and Réunion are relatively close, several factors explain why the auroras were more visible in Réunion. The primary reason is the difference in latitude and local observation conditions. Réunion, with its mountains and higher altitudes, offers better observation points less affected by light pollution, allowing for clearer views of celestial phenomena. However, some lucky Mauritians did manage to catch a glimpse of this magical event.
What are the risks?
While southern auroras are breathtaking, the geomagnetic storms that cause them can have significant and potentially dangerous impacts on Earth. These storms can disrupt power production and transmission, risking damage to electrical installations and transformers. They can also harm satellites, interfere with communications, and affect GPS systems. Additionally, they can disorient animals that use the Earth's magnetic field for navigation, such as whales and certain birds. In extreme cases, though rare, powerful geomagnetic storms could fry the electronic circuits in our phones, computers, and vehicles.
