Today's post is about the solar storms that affected the Earth on July 23, 2012. In a solar storm, a solar flare erupts from a sunspot, and extreme UV radiation and X-rays reach the Earth's atmosphere, which can interrupt radio broadcasts and mess up GPS communications. A little later, electrons and protons arrive and can damage satellites. Last come coronal mass ejections (CME), which is magnetized plasma that is delayed by about a day. This can cause huge electrical blackouts and loss of our running water through our pipes, since electric pumps wouldn't work.
In July 2012, two CMEs occurred that hit the STEREO-A spacecraft, and would have hit Earth if it occurred one week later, when Earth would have passed the ejection location in its orbit. This CME event could have been larger than the largest CME ever recorded, in 1859, named the Carrington event. The CME hit the earth head-on, and caused telegraph lines to spark around the world and set fire to telegraph offices. Auroras (northern lights) were seen as far south as Cuba! For a modern comparison, in 1989 a strong geomagnetic storm knocked out power across much of Quebec.
If the 2012 CMEs did hit the Earth directly, scientists speculate that they could have caused damage totaling $2 trillion. It could have fried transformers that weigh several tons that take years to repair. Losing power for several years would eliminate the use of much of our modern technology. "If an asteroid big enough to knock modern civilization back to the 18th century appeared out of deep space and buzzed the Earth-Moon system, the near-miss would be instant worldwide headline news." Scientists were able to collect so much data on the 2012 CME because the STEREO-A spacecraft was designed to withstand solar storms, and so it wasn't even damaged while taking a direct hit. It sits in interplanetary space and was able to continue collecting data because there is a weaker magnetic field than that around earth, and strong electric currents aren't generated by CMEs there that could damage spacecraft. Scientists predict there is a 12% chance that a solar storm as big as the Carrington event will hit Earth in the next 10 years. I wonder how we can best prepare for something like that . . . be able to switch everything to battery or gasoline-generated power?