How do solar flares affect humans?

Solar storms emit radiations, exposure to which is harmful to humans and can cause organ damage, radiation sickness and cancer. This is due to the fact that the Earths atmosphere acts as a protective shield for living beings, absorbing most of the radiation.

How fast do solar flares travel?

Flares can last minutes to hours and they contain tremendous amounts of energy. Traveling at the speed of light, it takes eight minutes for the light from a solar flare to reach Earth. Some of the energy released in the flare also accelerates very high energy particles that can reach Earth in tens of minutes.