It is difficult to comprehend the power of our Sun, a churning ball of hot gas 1.3 million times larger than Earth. It constantly emits the ‘solar wind’, a stream of energetic atomic particles, and routinely lashes out with coronal mass ejections, colossal outbursts of solar plasma flung into space.
Extreme solar events – such as arrivals of fast plasma clouds or high-speed solar wind streams – disturb our planet’s protective magnetic field, creating geomagnetic storms at Earth. Such an event happened in 1859, causing spectacular auroras and overheating telegraph wires but no lasting damage to the simple technologies then in use.
Today, a major solar event could seriously disrupt or damage 21st century systems that are critical to Europe’s daily economic functioning, such as navigation and telecom satellites, or power grids and communication services. According to recent estimates, a single, major space weather event could cause €15 billion in socio-economic damages to Europe, and even routine solar activity can have a costly effect on satellites and infrastructure on ground.
We cannot control our Sun, but timely alerts – like those to be enabled by ESA’s future Lagrange solar warning mission – will allow civil authorities and commercial actors to take protective measures, helping minimise economic losses and avoiding a disaster that would affect us all.
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