Huge Solar Eruption May 'Sideswipe' Earth on Thursday

Earth may be in the path of a type of sun explosion called a coronal mass ejection (CME) that is due to arrive on Thursday, according to space weather analysts.

If they are strong enough, CMEs can wreak havoc on electrical systems here on Earth by interacting with our planet's magnetic field. However, the CME that may arrive on Thursday is not expected to cause any issues.

The possible CME impact has been predicted by which states that the solar explosion "might sideswipe Earth's magnetic field on March 10" after having erupted from the sun's surface on March 7. It could spark a G1-class geomagnetic storm, the space weather analysis site said.

As of Wednesday morning the U.S. Space Weather Prediction Center (SWPC), which is part of the National Oceanic and Atmospheric Administration, had not issued a CME impact alert and did not warn of a G1 storm.

A G1 storm is the most minor type of geomagnetic storm—a space weather event that occurs when the Earth's magnetic field is disturbed by solar energy. In a G1 storm, it's possible that there could be a minor impact on satellite operations and weak power grid fluctuations could occur. Auroras may also be visible in northern U.S. states like Michigan and Maine.

A G5 storm is the most severe type. In a G5 storm, there would be widespread voltage control problems and power grid systems may experience complete collapse. Spacecraft would have trouble orienting themselves and exchanging data. High frequency radio transmission would be out, potentially for days. In addition, auroras may be visible in U.S. states as far south as Florida and southern Texas.

Such extreme events are thankfully rare, but significant storms do occur. In 2021, the SWPC issued a G3 geomagnetic storm watch alert for October 30 to October 31 following a significant CME that erupted from the sun on October 28.

One particularly energetic storm, called the Carrington Event, occurred in 1859 and caused damage to telegraph stations.

CMEs occur when the sun's magnetic fields get twisted by the movement of the star's interior. Eventually this built-up energy gets released and the magnetic fields explosively realign, releasing vast amounts of energy into space. CMEs are huge clouds of magnetized particles released from these explosions that can take just days to reach Earth from the sun.

CMEs are not to be confused with solar flares, which are also a result of these solar explosions but may not be quite as severe. Solar flares are flashes of light and energy from these explosions that hit Earth within minutes.

NASA describes the difference using an imaginary cannon, where the solar flare is the muzzle flash and the CME is the cannonball.

Solar flare
The sun seen emitting a solar flare, seen by NASA's Solar Dynamics Observatory in January, 2015. Solar flares and coronal mass ejections are the results of explosions of energy from the sun. NASA/SDO