On Earth, the main source of space weather is the Sun. The Sun was here before the Earth, and space weather events such as solar flares and coronal mass ejections (CME) have been occurring since before life began. But it’s only in the modern world that they’ve become a significant hazard. As long as people stayed at ground level and didn’t rely on electronic systems for navigation and communication, or on the electrical grid for power, they could remain blissfully unaware of solar activity. But in today’s world, with all our satellites and electronic aids, that’s no longer an option. Someone has to keep a constant eye on the vagaries of space weather, just as meteorologists do with ordinary weather.
The way space weather forecasters work is analogous to their terrestrial counterparts, combining data from a variety of sources – both on the ground and in space – with computer models to work out what’s likely to happen. Unlike terrestrial forecasts aimed at the general public, space weather forecasts are targeted at the business sectors most likely to be affected. The ESA’s Space Weather Network provides tailored services to a variety of industries, ranging from airlines and power distribution systems to spacecraft operators and auroral tourist agencies.