Last week, scientists waited in anticipation for two massive solar flares that were scheduled to hit the earth's magnetic field on September 11th and 12th, respectively. While the outbursts were not expected to be as powerful as the ones experienced in 2012, it was the back-to-back occurrence that had experts concerned about the damage they could cause to our satellites, electric grids and GPS systems.
The first, which reached Earth on Thursday night was pretty benign resulting in a modest G2 magnetic storm. However the one that impacted the planet's magnetic field at midday on Friday, was a slightly stronger X1 class flare. The combination of the two resulted in a fairly powerful G3 storm (the strongest being G5) that experts believed could last for up to several days and possibly disrupt our communication systems.
Fortunately, that did not happen. Instead, the two coronal mass ejections or clouds of fast moving particles that erupted from the sun's outer atmosphere, resulted in creating beautiful auroras for some lucky North American residents.
Solar flares or storms begin with an explosion usually above a sunspot, the area where strong magnetic fields poke through the sun's surface.
As the spots become unstable and explode, they release intense amounts of energy — the equivalent of a billion hydrogen bombs.
Called solar flares they resemble a flash of light and can reach earth within a short 8 minutes. When the flares hit either of the two poles, they excite the nitrogen and oxygen particles, resulting in what we call northern or southern lights.
The largest solar storm to ever hit earth was in 1859. It was called the Carrington Event after British astronomer Richard Carrington, who was the first scientist to connect the sun's activity with the Earth's geomagnetic disturbances. The storm was so powerful that the northern lights could be seen as far south as Cuba and Hawaii, while southern lights shone all the way up to Chile.They were rumored to be so bright that Northeastern USA residents used them to read newspapers! Though there were no satellites or GPS devices to destroy, the flares did set sparks and even burned down some telegraph equipment in the US.
While experts are relieved that the storms passed without incident, they are always on the lookout for solar activity. That's because though these blasts of radiation that are blocked by the magnetosphere and atmosphere, pose no risk to humans, the protons and other charged particles that follow within about 20 minutes, can be extremely destructive to our satellite systems, GPS tracking devices and power grids. This means that a truly massive storm, like the one that hit earth in 1859, could result in knocking out electricity grids across North America, leaving millions of people without power for months! Fortunately, the sun seems to have been relatively calm so far!
Resources: wikipedia.org, cnn.com, vox.com, space.com