Earth might experience some minor geomagnetic storms later this week if a slow-moving cloud of solar particles reaches Earth.
The prediction was made by spaceweather.com, a site that uses sun-monitoring data to produce space weather updates.
Geomagnetic storms are the results of changes to Earth's magnetic field due to the interactions between it and charged particles from the sun. If they're strong enough, these storms can interfere with communication networks and the power grid.
It's unlikely this will be the case with the potential upcoming storm, however, which is only expected to be a G1-class storm—the mildest type, according to the National Oceanic and Atmospheric Administration's Space Weather Prediction Center (SWPC) space weather scale.
The SWPC states that G1-class storms may cause weak power grid fluctuations and have a minor impact on satellite operations. In addition, auroras may be visible in the sky in lower latitudes than normal, such as over U.S. states like northern Michigan and Maine.
The possible storm will be caused by a cloud of particles ejected from "an unstable filament of magnetism" on the sun on July 15, according to spaceweather.com, which stated an expected arrival time of between July 20 or July 21.
In addition, solar physicist Tamitha Skov shared a NASA prediction model to Twitter showing what she said would be a "direct hit" from a July 15 solar ejection, but with an earlier impact date of July 19. It's unclear if this is the same ejection.
The solar ejection can also be seen in a video from NASA's Solar Dynamics Observatory that day, which shows a very brief flash of material racing away from the sun's surface in the mid-afternoon right at the start of this clip.
These clouds of particles are known as coronal mass ejections (CMEs) and are common occurrences. However, only once every couple of weeks or so does one end up heading for Earth.
CMEs can consist of billions of tons of material from the sun's atmosphere and carry an embedded magnetic field. They are released from the sun when twisted magnetic field lines suddenly reconfigure themselves.
The speed of CMEs can vary widely, with some capable of reaching Earth in as little as 15 to 18 hours according to the SWPC. However, the July 15 ejection is traveling particularly slowly and is predicted to make contact with Earth between five and six days after leaving the sun. The SWPC had not issued any warnings or alerts as of Monday. In any case, it's unlikely to cause any problems for the general public even if it does hit Earth.
Newsweek has previously spoken to a space weather expert to learn what would happen if a seriously big geomagnetic storm did occur as a result of a massive solar flare or CME. Such events could lead to trillions of dollars' worth of damage to infrastructure as well as significant disruption.