A cloud of “dark plasma” erupted from the sun on Sunday and is predicted to make contact with Earth on Wednesday, giving rise to the possibility of a minor geomagnetic storm.
The eruption of material is known as a coronal mass ejection (CME)—a cloud of charged solar gas and magnetic fields. It was launched toward Earth on August 14 from a region of the sun known as AR3076.
Observations from NASA‘s Solar Dynamics Observatory (SDO), seen above, show the moment the CME was launched from the sun’s surface, appearing as a brief dark cloud towards the end of the clip at around 11:30 UT.
Solar activity news site spaceweather.com stated on Monday morning that the “plume of dark plasma” was traveling at over 1.3 million miles per hour. At that speed, it’s expected to take a few days to travel the distance from the sun to the Earth.
CMEs are launched from areas of the sun known as sunspots, which appear to be dark patches on the sun’s surface—though certain NASA footage may also make them appear bright.
The reason sunspots appear different to the surrounding area is because they are located in regions of the sun where magnetic fields are particularly strong—so strong that they prevent heat from reaching the sun’s surface from its core. This makes sunspots cooler than the surrounding area.
When these intense magnetic fields suddenly shift or realign, solar material and radiation are ejected away at high speed. Sunspots can cause CMEs as well as solar flares, which are both examples of space weather.
Some CMEs have the potential to cause disruption to modern life due to the effect they have on Earth’s magnetic field. CMEs can also cause electrical disturbances that might affect power grids, cause increased drag on satellites, and even cause auroras to appear in parts of the world where they’re rarely seen. The effects of CMEs on Earth are referred to as geomagnetic storms.
The U.S. National Oceanic and Atmospheric Administration’s (NOAA) Space Weather Prediction Center (SWPC) said in an alert on Sunday that the expected arrival of Wednesday’s CME should only cause a minor geomagnetic storm.
The potential effects include weak power grid fluctuations, a minor impact on satellite operations, and possibly auroras that may be visible in U.S. states like northern Michigan and Maine.
The SWPC has predicted that the storm will be a G1-class storm—the mildest possible score on the geomagnetic storm scale, which goes up to G5. G1 space weather storms are common, sometimes occurring multiple times a month. For most people on Earth, their effects aren’t noticeable.
G5 storms, on the other hand, have the potential to cause the complete collapse of some power grid systems, disruption to high frequency radio communications for days, and auroras in states as far south as Florida and southern Texas. Such storms are rare.