CME TO STRIKE VENUS: A CME launched into space by yesterday's X-flare (described below) won't strike Earth, however, it will hit Venus according to a NASA model. The strike on Venus (Feb. 18th) will probably erode a small amount of Venus's upper atmosphere. CMEs do not erode Earth's atmosphere because, unlike Venus, our planet is protected by a global magnetic field. CME impact alerts: SMS Text

AN X-FLARE FROM 'THE DANGER ZONE': Sunspot AR3576 erupted on Feb 16th (0653 UT), producing a brief but intense X2.5-class solar flare. NASA's Solar Dynamics Observatory (SDO) saw huge plumes of plasma fly away from the blast site:

This composite was created by Senol Sanli of Bursa, Turkey, using data from SDO

As these images show, AR3576 is near the sun's western limb, no longer facing Earth. You might think that means our planet is safely outside the line of fire. In fact, the opposite is true. AR3576 is entering a 'danger zone' where the sun and Earth are magnetically connected. This phenomenon is explained in more detail below (See "The Danger of Sunspots That Don't Face Earth").

The flare hit Earth with a pulse of energetic protons, shown here in a plot from NOAA's GOES-18 satellite:

The magnetic connection between Earth and AR3576 allowed this pulse to reach us despite the fact that the sunspot is not facing our planet. Notably, the wave of particles was relatively rich in "hard protons" with energies > 50 MeV, which are effective at upsetting satellite electronics.

Another X-flare from AR3576 this weekend could add to the particle count and trigger a full-fledged radiation storm. Possible effects include high-latitude radio blackouts, fogged cameras on Earth-orbiting satellites, and elevated levels of radiation on commercial air flights. Stay tuned. Solar flare alerts: SMS Text