STRONG SOLAR ACTIVITY: For the third day in a row, active sunspot 1261 has unleashed a significant M-class solar flare. The latest blast at 0357 UT on August 4th registered M9.3 on the Richter Scale of Flares, almost crossing the threshold into X-territory (X-flares are the most powerful kind). The number of energetic protons around Earth has jumped nearly 100-fold as a result of this event.
The eruption propelled a bright coronal mass ejection (CME) toward Earth.
Moving at an estimated speed of 1950 km/s, this CME is expected to sweep up two earlier CMEs already en route. Analysts at the GSFC Space Weather Lab say the combined cloud should reach Earth on August 5th at 13:55 UT plus 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." High-latitude sky watchers should be alert for auroras.