A massive coronal hole has formed in the sun's atmosphere, unleashing a powerful stream of solar wind toward Earth. Nearby, a second, slightly smaller coronal hole is also directing solar wind our way. There is a great chance of strong northern lights, especially at high latitudes this weekend. Recent solar activity has prompted the U.S. National Oceanic and Atmospheric Administration's (NOAA) Space Weather Prediction Center to issue a minor G1 geomagnetic storm warning.
While geomagnetic storm watches of this level are not uncommon, it's not something to ignore. A recent uptick in geomagnetic activity produced stunning northern lights displays that reached deep into mid-latitudes over New Year's. Aurora chasers at high latitudes may be in for another spectacular treat. Make sure those camera batteries are charged! Coronal holes appear as dark areas in the sun's corona — the outer atmosphere — when viewed in extreme ultraviolet (EUV) and soft X-ray imagery, according to NOAA. These 'holes' appear dark because they are cooler than the surrounding material. Coronal holes allow solar wind to escape from the sun more readily, resulting in streams of relatively fast solar wind. When directed at Earth, these solar wind streams can interact with our planet's magnetic field and trigger geomagnetic storm conditions.