The largest solar flare in the past 12 years was recorded on Sept. 6, 2017. It was an ¨X-Class¨ flare, which reached the energy level of X-9.3. The peak energy was around 8:02 a.m. (Eastern Daylight Time). The shock of the radiation, which arrived from the sun, caused a radio blackout for about an hour. It also affected satellites and disrupted the Global Positioning System (GPS) that is used for worldwide navigation.
The previously, largest solar flare was recorded in September 2005. At that time, an X-17 hit the Earth. The X-Class is the most intense solar flare. With a logarithmic scale, an X-2 level is twice as intense as an X-1 level. The greatest solar flare ever measured happened during April 2001. It was an X-20.
Newsweek reported that the recent solar flare was measured by NASA’s Solar Dynamics Observatory. This facility and program constantly monitors space weather and sun spot activity.
The NASA agency said that harmful radiation of this type, caused by a solar flare, cannot directly harm humans on Earth because it is blocked by the Earth´s atmosphere. What it can do, however, is interfere at the atmospheric level where important communications pass through such as satellite, radio, mobile phone, and GPS signals.
Radio blackouts and communication disruptions cause a dangerous condition for airplanes in flight if the pilots lose communication with air traffic control. Moreover, this disruption can harm emergency relief efforts, such as those ongoing for the massive hurricanes we are currently experiencing.
Strong geomagnetic pulse warnings are in effect from Sept. 7 through Sept. 9, 2017, because a coronal mass ejection (CME) of energy will hit the Earth on September 8 or 9.
Solar flares and CMEs are a phenomena that occurs frequently during the same period of solar activity. A strong CME has the ability to destroy telecommunications equipment that is not ¨hardened¨ with protection against the energy burst. President Obama issued an executive order during 2016 to tell the U.S. government to prepare for major disruptions caused by a massive CME.
In 1859, a gigantic solar storm occurred. It was called the "Carrington Event." Telegraph systems all across North America and Europe failed due to the solar energy hitting Earth during this event. The colorful auroras, which are normally only seen in the Arctic, could be seen as far south as parts of the Caribbean. This is quite a serious threat to life on Earth as we know it. Because of our reliance on telecommunications, if a similar storm such as the Carrington Event hit Earth today, the damages would be in the multiple trillions of dollars, exceeding any other known natural disasters.