Giant Sunspot, Larger Than Earth's Diameter, Appears On Sun

Giant Sunspot, Larger Than Earth's Diameter, Appears On Sun
An enormous sunspot, labeled AR1944, slipped into view over the sun's left horizon late on Jan. 1, 2014. The sunspot steadily moved toward the right, along with the rotation of the sun, and now sits almost dead center, as seen in the image above from NASA's Solar Dynamics Observatory.

STORM WARNING
NOAA forecasters estimate a 90% chance of geomagnetic storms on Jan. 9th when a CME is expected to hit Earth's magnetic field. The speed of the solar wind around Earth could spike to 700 km/s (1.6 million mph) shortly after the impact, sharply compressing Earth's magnetosphere. High-latitude sky watchers should be alert for auroras.