The Harvard Smithsonian Center for Astrophysics released the latest information on the July 31/August 1 activity on the Sun that is just now reaching Earth. They predict we’ll have multiple opportunities for a display of the Northern Lights over the next two days. The latest word from the solar scientists is that the Sun erupted not just once, but four times. All four coronal mass ejections are headed toward Earth.
Space weather forecasts are even more challenging than regular weather forecasts, said Dr. Leon Golub, and a coronal mass ejection is like a hurricane: it’s large and fuzzy, and doesn’t always move at the same speed. Currently, the estimated arrival times are:
Wednesday, Aug. 4 – 3:00 a.m. EDT (0700 GMT on Aug. 5; aurorae not visible in daylight)
Wednesday, Aug. 4 – 1:00 p.m. EDT (1600 GMT, again the daylight issue)
Wednesday, Aug. 4 – 8:00 p.m. EDT (0000 GMT on Aug. 5)
Thursday, Aug. 5 – 2:00 a.m. EDT (0600 GMT)
Any one of these events may or may not generate an aurora. It depends on details like magnetic field orientation. If the magnetic field in the oncoming solar plasma is directed opposite Earth’s magnetic field, the result could be spectacular aurorae. If the fields line up, the coronal mass ejection could slide past our planet with nary a ripple.
The Center for Astrophysics suggested these two resources:
Map of current auroral activity
Chart of proton flux (watch for the numbers to go up as each wave arrives)