It started several months ago -- sunspots flickered, more and more solar flares arched out into space, and a ripple of changing current made its way past Pluto to the outer reaches of our solar system.
The sun was flipping its magnetic polarity -- an event that happens every 11 years.
"This is exciting because this is kind of a probe into the internal workings of the sun, which is actually really hard for us to get a handle on," said Seth Redfield, who teaches astronomy at Wesleyan University.
Scientists still don't fully understand why the sun changes polarity, but they observe its occurrence in part by monitoring sunspots and other activity on the solar surface.
"You've probably seen beautiful images of the sun where you have these artful magnetic loops that are coming off. And you have a flare. And it just looks amazing," Redfield said.
Scientists say this solar cycle, called "Cycle 24," has been pretty low key. That's good news for satellites and the electric grid, which can get fussy when the earth's magnetic field gets bombarded by solar radiation.
"We should not be alarmed by this at all," Redfield said. "This is just kind of what the sun does."
One other interesting note -- the sun's hemispheres are shifting polarity at different rates. The northern hemisphere flipped earlier this summer. The southern hemisphere could reverse itself any day now.
In the meantime, scientists will be glued to their computers.