Northern lights, which are usually limited to higher latitudes, have recently amazed many people with a festival of colors in the night sky in Mexico, southern Europe and Africa, reports AFP, quoted by BTA.
For the scientists responsible for protecting planet Earth from powerful solar storms, the show is not so enticing.
"We need to understand that behind this beauty there is danger," Kantan Verspiren, coordinator of the space security program at the European Space Agency (ESA), told AFP.
Mike Bethue of the US Space Weather Prediction Center agrees, preferring to "focus on the potentially harmful impacts" of solar storms. They can have negative consequences for power grids and satellites, or expose astronauts to dangerous radiation.
The glow that appeared on May 11 and 12 was caused by the most powerful geomagnetic storm since the one in October 2003, which caused a blackout in Sweden and damaged grids in South Africa, notes AFP.
The damage is now apparently less, although it will be several weeks or months before satellite companies reveal any damage, Bethui said.
There are several cases of automated American tractors that have stalled when their GPS system has failed.
Geomagnetic storms are formed when streams of electrically charged particles are ejected from the surface of the Sun and reach the magnetosphere - the Earth's geomagnetic field, notes AFP.
There is expected to be "intense activity over the next few days", ESA's Alexi Glover told AFP.
Solar activity is "not quite over,", Glover said, noting that it is difficult to predict the strength of any flares and whether they will cause the northern lights.
Astronomers know only that the Sun is approaching the peak of its activity in its eleven-year cycle. Therefore, the risk of another geomagnetic storm is highest "between now and the end of next year,", says Mike Bethue.
Geomagnetic storms create an electrical charge that destroys satellite circuits and overloads power grids. The most famous example of this so far is the so-called the Carrington event of 1859, which caused sparks in telegraph stations. Some of these sparks were so powerful that the devices continued to work even without connection to the electrical network, AFP recalls.
What would happen if a geomagnetic storm of this magnitude occurred again? Most countries have strengthened their electricity grids to avoid prolonged blackouts, as in Sweden in 2003 and Canada in 1989.
Astronauts are particularly at risk from high doses of radiation, but they have the opportunity to protect themselves in a special area of the International Space Station, notes AFP.
Radiation accompanying a geomagnetic storm can "penetrate the fuselage" on a plane near the North Pole, says the American expert Bethui. Sometimes airlines change the routes of their planes during an extreme storm.
Several upcoming missions are expected to improve forecasting of solar activity to give Earth more time to prepare, notes AFP.