RETURN OF THE BIG CORONAL HOLE: At the end of October, a hole in the sun's atmosphere lashed Earth's magnetic field with solar wind, sparking moderately-strong geomagnetic storms and almost a full week of Arctic auroras. News flash: It's back. The same "coronal hole" is turning toward Earth again. NASA's Solar Dynamics Observatory photographed the structure on Nov. 20th:
NOAA forecasters expect the leading edge of the emerging solar wind stream to reach Earth on Nov. 22nd, bringing with it a chance of G1-class geomagnetic storms. Stay tuned! Free: Aurora Alerts.