GEOMAGNETIC STORM WATCH G2. A halo CME is heading for Earth. NOAA's forecast model predicts it will arrive during the early hours of July 24th around 02:00 Universal Time, potentially sparking a G2-class geomagnetic storm. If that forecast is correct, the storm could produce photographic auroras over northern-tier US states during the night of July 23rd or 24th, in North American time zones. FARSIDE CME PEPPERS EARTH WITH HARD PROTONS. Something just exploded on the farside of the sun--and it managed to touch Earth. Debris from the blast emerged in the form of a full halo CME, shown here in a movie from the Solar and Helospheric Observatory SOHO. Shock waves at the leading edge of the CME are accelerating protons and spraying them throughout the solar system. Some of those protons are raining down on Earth right now. NOAA's GOES-18 satellite is monitoring an intensifying S1-class solar radiation storm rich in hard protons. Hard protons are good at charging spacecraft bodies, fogging their cameras, and causing reboots of onboard computers. Indeed, you can see a hint of the "fog" in the SOHO movie above. Each speckle is a hard proton striking the spacecraft's digital camera. Europe's Solar Orbiter SolO spacecraft is going to get good data on this event. A NASA model of the CME predicts that it will directly hit SolO on July 24th. Stay tuned for updates from the spacecraft's energetic particle detectors. stay tuned for more. space weather