The Earth’s magnetic field is a puzzle. It protects us from the Sun, it provides us with directions, and it seemingly unchanging. But, it does change – lot. In fact we know that not only does it completely flip, but it does so on a seemingly random basis. A new European mission, Swarm, has just launched to try to help to solve this mystery. It’ll help to map the Earth’s global magnetic field in unprecedented detail.
Swarm’s data should help scientists understand better how the Earth’s field is generated, and why it appears to be weakening. Strangely, our magnetic field seems to have weakened by more than 10% in the last 20 years, and it appears to be moving around faster. Speculation is growing that we may be on the verge on a new flip. North would become south, and vice versa, something that hasn’t happened for almost 800,000 years. We’re actually well overdue a flip. The main worry we have is what happens during the flip. It must weaken, flip and strengthen, and during the weak period, we’re very concerned about whether our protecting from the Sun might be somewhat absent.