Scientists were treated to quite the show on the surface of the sun recently, with multiple huge solar flares including one absolute giant: an X9.3, the largest seen in 12 years. Scientists have seen six solar flares from Active Region 2673 over the course of about a week, a huge amount of activity that hasn’t been seen in years.

Solar flares fall into three classes: Cs, followed by Ms, which are 10 times more powerful, and then Xs, which are 10 times more powerful than the Ms. These solar flares will send out gigantic amounts of energy that are known as “coronal mass ejections” (CMEs), causing problems with power grids and satellites.

These solar flares also create incredible shows here on Earth known as the Northern and Southern Lights, when the charged particles slam into the Earth’s magnetic field.