But that could change. "Based on what we're seeing in the data, it appears there's a good chance of a strong geomagnetic storm somewhere around the G5 level in the next 24 hours," says Dr. Pulkkinen.
Whether this happens could largely be a question of the storm’s orientation.
If the billions of tons of charged particles hitting the Earth strike it in a northward orientation – which is the same direction as the Earth's own magnetic field – then it's "like water off a duck's back," says Daniel Baker, director of the Laboratory for Atmospheric and Space Physics at the University of Colorado at Boulder.
But if the reverse occurs, which seems possible based on the data he's seeing, "now the fields collide like they love each other, there's and embrace, and energy from the [coronal mass ejection] has opened the gate and floods into Earth's vicinity."
"This is not a bell-ringer yet,” Dr. Baker says. “But it is a storm that looks like it is oriented in a way that should drive it to greater heights."
Intense debate has swirled over and what, if anything, to do about solar storms beyond reactive, defensive actions. Only a handful of such storms has had any serious impact during the past century. Still, societies are more dependent on power grids than ever – and damage to the grid could be severe in some cases.
The power grid is 10 times larger than it was in 1921, when the last solar super storm hit, effectively making it a giant new antenna for geomagnetic current. A far stronger solar outburst could overload and wreck hundreds of crucial high-voltage transformers nationwide, blacking out 130 million people for months and costing as much as $2 trillion, according to a 2010 Oak Ridge National Laboratory study.