At 8:15am EDT yesterday, a coronal mass ejection (CME) erupted from sunspot 1302, sending charged particles streaming in our direction.
The Goddard Space Weather Lab reported a strong compression of Earth's magnetosphere. And simulations showed solar wind plasma penetrating right into geosynchronous orbit, meaning that satellites could be directly exposed to solar wind plasma and magnetic fields.
Lucky viewers with clear skies may have seen auroras last night, and there's a chance of more tonight.
Sunspot 1302 has been particularly active over the last few days. On Saturday, it unleashed an X1.9-category flare, followed by M8.6 and M7.4 flares later the same day and an M8.8 flare early on Sunday.
"None of the blasts have been squarely Earth-directed, but this could change as the sunspot turns toward our planet in the days ahead," says NASA. "AR1302 is growing and shows no immediate signs of quieting down."
It's possible that GPS systems could be affected today. The NOAA says that solar activity's exected to remain moderate during the course of the day, tailing off over the next few days.
And, it warns, another CME could be on the way, with the sunspot showing no signs of quietening down - indeed, it may be getting more lively.
"The spot on the sun that produced Saturday's coronal mass ejection remains active and is well positioned to deliver more storm activity in the next several days," it says.