Three strong solar flares erupted from the sun on August 25, including a powerful M6.9 solar flare that sent a coronal mass ejection toward Earth. Early models put the CME on track to reach Earth later this week, with a possible arrival Friday morning EDT.
The flare peaked at 6 a.m. EDT and came during a burst of activity that produced multiple radio blackouts across Earth. The event sits in the second-strongest category of solar flares, which are ranked from A, B, C, M and X.
NASA Solar Dynamics Observatory
NASA's Solar Dynamics Observatory captured images of the flares as they unfolded. NASA says solar flares can affect radio communications, electric power grids and navigation signals, and they also pose a risk to spacecraft and astronauts.
The CME now matters because its magnetic field has to reach Earth and interact with it before any geomagnetic storm develops. Scientists are waiting to see how strong that interaction will be, and that strength will determine the exact arrival time.
Earth and North America
If the CME arrives with enough force, it could trigger a geomagnetic storm and produce auroras for thousands of skywatchers. Only a limited number of locations in North America may be able to see the display, and the view could improve if the CME lines up with a high-speed solar wind stream.
That combination could increase geomagnetic activity, but early models suggest Earth may only take a glancing blow when the CME arrives around 6 to 7 a.m. EDT on Friday. The difference between a direct hit and a glancing pass will decide how much of the storm reaches Earth and how far the aurora may extend.
