The sun unleashed another X-class solar flare today, causing a deep shortwave radio blackout over southeast Asia and Australia.  Intensifying solar activity has resulted in more than 19 flares during the past 24 hours alone. Even farside sunspots are getting in on the act. Full story @ Spaceweather.com.

X-CLASS SOLAR FLARE: The sun just produced another X-flare. Earth-orbiting satellites detected the X2.2-class explosion on April 20th @ 0357 UT. Remarkably, it came from a farside sunspot. The source of the flare is AR2992, which yesterday rotated over the southwestern limb of the sun.

The sunspot is no longer visible at all. It is hidden behind the edge of the solar disk. Because the blast site was eclipsed by the body of the sun, the actual flare was almost certainly stronger than its nominal rating of X2.2.

Radiation from the flare caused a shortwave radio blackout over southeast Asia and Australia: blackout map. Mariners and ham radio operators in the area may have noticed loss of radio contact at frequencies below 30 MHz for as much as an hour.

Shortly after the flare, the US Air Force reported a Type II solar radio burst--a natural form of radio noise produced by shock waves in the sun's atmosphere. Ironically, this radio burst filled the loudspeakers of shortwave radios on the dayside of Earth with static during the radio blackout mentioned above. Terrestrial radio stations were briefly replaced with solar noise.

SOHO coronagraphs have since detected a CME emerging from the blast site:

This CME will not hit Earth. It is well outside the strike zone--no surprise considering the farside location of the sunspot.

Stay tuned for updates. Solar flare alerts: SMS Text