Solar storms are some of the most dangerous phenomena that can hit our planet, and they can cause billions of dollars in damage over the course of just a few hours. They pose significant threats to the high-tech global infrastructure, the power grids, the satellite networks, as well as to the astronauts aboard the International Space Station. Therefore, finding ways of anticipating them might end up saving lives and considerable amounts of money. Experts at the University of Alberta have recently managed to pinpoint the place where such a storm would hit, using readings from the THEMIS craft.

At this point, NASA has one of the most advanced defenses in the world, namely its twin solar observatory STEREO. Made up of two almost identical spacecraft, one moving “ahead” of the planet in its orbit, and the other “trailing” behind, the instrument is able to photograph the surface of the Sun in 3D, and can discover forming solar flares at least a few days before they separate from the star, journey to the Earth, and discharge in the atmosphere. Estimates say that such an event can unleash more than 50 gigawatts of power, the output equivalent of the world's ten largest power plants.

High-energy particles, heavily charged, are emitted from the star, and are brought at high speed directly into the upper layers of the atmosphere. When that happens, the Earth's magnetic field protects us from being swiftly destroyed. As the energy discharges into our protective shield, some of it is dissipated at the poles, and can be observed as the Northern and the Southern Lights. The remaining power can create geomagnetic substorms in the atmosphere.

“Substorm onset occurs when Earth's magnetic field suddenly and dramatically releases energy previously captured by the solar wind,” NASA Goddard Spaceflight Center expert David Sibeck explained. He is the project scientist for the American space agency's Time History of Events and Macroscale Interactions During Substorms (THEMIS) instrument. UA Physicists Jonathan Rae and Ian Mann followed such a storm, miles in the atmosphere, and used an array of ground-based observatories and five satellites from the THEMIS mission to assess its behavior.

“We see the benevolent side of space storms in the form of the Northern Lights. When electrically charged particles speed toward Earth and buffet the atmosphere, the result is often a dancing, shimmering light over the polar region,” Mann shared. But that's just the positive aspect of solar storms. When one of a larger intensity occurs, the magnetosphere cannot hold it all back, and some of the radiation passes through, wreaking havoc below.