via Wired: Wired Science by Adam Mann on 3/8/12
The most powerful solar storm in five years hit Earth on March 8, and could create northern lights far south of their usual range.
On March 6, the sun produced two enormous X-class flares – the most powerful types of blasts to erupt from the sun’s surface – that flung waves of charged particles into space. The particle bursts are called coronal mass ejections, or CMEs, and as they hit Earth’s atmosphere they can disrupt communication satellites and power grids. But the interaction of CMEs with Earth’s magnetic field also produces the incredible displays known as the northern lights.
When the storm reached Earth, it was slightly weaker than expected, and the alignment of Earth’s magnetic field with the CME’s magnetism further weakened the storm. On the NOAA Space Weather Prediction Center’s Facebook page, the effect was likened to two bar magnets placed side-by-side with their poles misaligned. But NOAA goes on to note that the storm may take 24 hours to completely pass and could intensify further. Officials predict a “strong” geomagnetic storm before the CME is done.
If the storm reaches predicted intensities, it could cause northern lights as far south as geomagnetic latitude 50 (this is not identical to geographic latitude). This includes most of the northeastern U.S., the upper Great Plains region, and Washington state. You can check your geomagnetic latitude at the SWPC website.
If you’re in line to potentially see the northern lights tonight, you can increase your chances by getting away from bright cities and looking for clear, cloudless skies. Any amateur photographers can send their best shots to us.
The sun is currently waking up from a lull in its 11-year solar cycle. The next several years should see increased activity, and there’s a real possibility of a dangerously strong solar storm occurring in the next decade. In addition to the double burst on March 6, another powerful X1.1-class flare erupted from the sun’s surface on March 4, but its CME missed Earth.
NASA has also built an app that can send the most up-to-date space weather information directly to your smartphone.