Major farside coronal mass ejection (CME) and radiation storm

A spectacular full-halo coronal mass ejection (CME) erupted on the farside of the Sun on September 5, 2022. The source is Active Region 3088, which is expected to return to Earth’s view in about a week.

The CME is heading to Venus, with the impact expected today or tomorrow, September 8. This is the second significant CME to hit Venus within a week.

“This is no run-of-the-mill event,” says George Ho of the Johns Hopkins Applied Physics Lab and the principal investigator for an energetic particle detector onboard Europe’s Solar Orbiter spacecraft.¹ “Many science papers will be studying this for years to come.”

Interestingly, Solar Orbiter was near Venus at the time the first CME reached the planet and its ‘in situ’ instruments recorded a wealth of data and beamed it back to Earth.

“I can safely say the September 5^th event is one of the largest (if not THE largest) Solar Energetic Particle (SEP) storms that we have seen so far since Solar Orbiter launched in 2020,” says Ho. “It is at least an order of magnitude stronger than the radiation storm from last week’s CME.”

“In fact, the >10 MeV and >50 MeV particle intensity has not subsided since the beginning of the storm yesterday,” adds Ho.

“This is indicative of a very fast and powerful interplanetary shock, and the inner heliosphere may be filled with these high-energy particles for a long time. I think I’ve only seen a couple of these in the last couple solar cycles.”

The source of the CME is most likely AR3088, which is expected to turn into Earth view in about a week.

References:

¹ Major farside CME and radiation storm – SpaceWeather.com – September 7, 2022

Featured image credit: NASA/STEREO-A COR2