For the most part, the Earth’s magnetic field protects humans from the barrage of radiation, but solar storms can affect satellite-based technology.
Solar winds can heat the Earth’s outer atmosphere, causing it to expand.
This can affect satellites in orbit, potentially leading to a lack of GPS navigation, mobile phone signal and satellite TV such as Sky.

McIntosh winces at the thought of what a massive storm might do: “Could you imagine DC or New York City being without power for six months, or eight months a year because of a solar event that they didn’t forecast well?”

On August 4, an aurora shone so luminously that shadows were cast was seen from the southern coast of the United Kingdom[1] and shortly later as far south as Bilbao, Spain at magnetic latitude 46°.[38] Extending to August 5, intense geomagnetic storming continued with bright red (a relatively rare color associated with extreme events) and fast-moving aurora visible at midday from dark regions of the Southern Hemisphere.[39]
Radio frequency (RF) effects were rapid and intense. Blackouts commenced nearly instantaneously on the sunlit side of Earth on HF and other vulnerable bands. A nighttime mid-latitude E layer developed.[40]
Geomagnetically induced currents (GICs) were generated and produced significant electrical grid disturbances throughout Canada and across much of eastern and central United States, with strong anomalies reported as far south as Maryland and Ohio, moderate anomalies in Tennessee, and weak anomalies in Alabama and north Texas. The voltagecollapse of 64% on the North Dakota to Manitobainterconnection would have been sufficient to cause a system breakup if occurring during high export conditions on the line, which would have precipitated a large power outage.

On September 1–2, 1859, one of the largest recorded geomagnetic storms (as recorded by ground-based magnetometers) occurred. Auroras were seen around the world, those in the northern hemisphere as far south as the Caribbean; those over the Rocky Mountains in the U.S. were so bright that the glow woke gold miners, who began preparing breakfast because they thought it was morning.[6]People in the northeastern United States could read a newspaper by the aurora’s light.[11] The aurora was visible from the poles to the low latitude area[12], such as south-central Mexico[13], Queensland, Cuba, Hawaii,[14] southern Japan and China,[15] and even at lower latitudes very close to the equator, such as in Colombia.[16] Estimates of the storm strength range from −800 nT to −1750 nT.[17]
Telegraph systems all over Europe and North America failed, in some cases giving telegraph operators electric shocks.[18]Telegraph pylons threw sparks.[19] Some telegraph operators could continue to send and receive messages despite having disconnected their power supplies.[20]