ONE DOWN, TWO TO GO: As predicted by analysts at the GSFC Space Weather Lab, the first of three CMEs produced by the recent spate of flare activity reached Earth during the late hours of August 4th. The impact was weak and is not expected to produce strong geomagnetic storms. Two more CMEs are still on the way and, as described below, they may have merged into a single cloud that could produce significant storming when they reach Earth on August 5th at 10:00 UT (plus or minus 7 hours). A new model of all 3 CMEs is now available; stay tuned for updates.

STRONG SOLAR ACTIVITY: On August 4th, active sunspot 1261 unleashed a strong solar flare, the third in as many days. The blast, which registered M9.3 on the Richter Scale of Flares, hurled a bright coronal mass ejection (CME) almost directly toward Earth. Click on the image to view a movie of the expanding cloud recorded by the Solar and Heliospheric Observatory:

Note: The many speckles in this movie are caused by energetic solar protons hitting the camera.

Moving at an estimated speed of 1950 km/s, this CME is expected to sweep up an earlier CME already en route. Analysts at the GSFC Space Weather Lab say the combined-CME should reach Earth on August 5th at 10:00 UTplus or minus 7 hours: “The impact on Earth is likely to be major. The estimated maximum geomagnetic activity index level Kp is 7 (Kp ranges from 0 – 9). The flanks of the CME may also impact STEREO A, Mars and Mercury/MESSENGER.”

fr/spaceweather.com