GEOMAGNETIC STORM WARNING: An explosion on the Sun today triggered a
solar proton storm around our planet and hurled a bright coronal mass
ejection (CME) into space. Although the fast-moving (~1100 km/s) CME was
not squarely Earth-directed, it could deliver a glancing blow to Earth's
magnetosphere as early as Dec. 28th Universal Time -- that is, Thursday
night for North Americans, Friday morning for Europeans. NOAA forecasters
estimate a 10% chance of severe geomagnetic storms at middle latitudes
when the expanding cloud sweeps past Earth. Sky watchers along the
northern tier of US states (and similar latitudes) should be alert for
auroras during the nights ahead.

• Space Weather