A filament of hot gas connecting two sunspots group erupted and sent a pulse of plasma into space the morning of August 4 (CDT). Earth is expected to receive at least a glancing blow from the material in the next couple days.
The Kp index, a fairly reliable indicator of geomagnetic (aurora) activity has crept up to just below minor storm level tonight. We’re clouded out in Duluth, Minn. but observers with clear skies living in the northern U.S. and southern Canada may want to keep an eye out tonight for northern lights. Truth in advertising: this is not expected to be a major storm.
Skies in our region are expected to clear tomorrow evening when auroras are again likely. The cause goes back to a coronal mass ejection (CME) on August 4. when a filament – a long arching garland of incandescent hydrogen gas – became unstable and erupted. You can see it fly away in the video; it’s the dark streak in the early images.
The aurora often starts early in the evening very low in the northern sky as a pale, arc-shaped glow. Peak activity is usually around midnight-1 a.m.