Yesterday, the US space agency spotted the Sun emitting a strong flare from an active sunspot. NASA’s SDO has been observing the Sun for over a decade and examining how solar activity is created and how space weather comes from that activity. The observatory recorded an extreme ultraviolet flash of an active sunspot emerging above the southeastern limb of the Sun.
The NASA statement said: “Solar flares are powerful bursts of energy. Flares and solar flares can impact radio communications, power grids and navigation signals, and pose risks to spacecraft and astronauts.
“This rocket is classified as a Class X rocket.
“Class X denotes the most intense flares, while the number provides more information about its strength.”
Spaceweather.com noted that: “Radiation from the flare ionized the top of the Earth’s atmosphere, causing a strong shortwave radio outage over the Atlantic Ocean and Europe.
“Signals below 30 MHz were attenuated for over an hour.”
Energy can be released from active regions of the Sun in two key forms: solar flares, which are sudden flashes of radiation, and so-called coronal mass ejections, or CMEs.
A CME is one of the most powerful forms of a solar storm and occurs when the Sun spits out a cloud of charged particles and electromagnetic fluctuations.
If large enough, such storms could potentially wreak havoc on Earth, inducing fluctuations in the power grid, disrupting high-frequency radio signals and interfering with the operations of satellites in low Earth orbit.
In September 1859, the Earth was shaken by the strongest geomagnetic storm on record – the so-called “Carrington Event”, which occurred as a result of CME.
READ MORE: Larger-than-Earth sunspots appear and trigger strong flares
According to the US National Oceanic and Atmospheric Administration: “Under normal conditions, high frequency (HF) radio waves are capable of supporting communication over long distances by refraction through the upper layers of the ionosphere.
“When a sufficiently strong solar flare occurs, ionization occurs in the lower, denser layers of the ionosphere (the D-layer), and the radio waves that interact with the electrons in the layers lose energy by due to the more frequent collisions that occur in the higher density environment of the D layer.
“This can lead to degradation or complete absorption of HF radio signals.”
Eventually, this results in a radio failure, that is to say the absence of high frequency communications, mainly impacting the 3 to 30 MHz band.