NASA Space Alerts(@NASASpaceAlerts):It’s #SunDay! Here’s your space weather report for the week of Sept. 11 - Sept. 17: • 0 M-class flares • 0 C-class flares (only counted if associated with coronal mass ejections) • 17 coronal mass ejections • 0 geomagnetic storms This video from NASA’s Solar Dynamics Observatory shows the week’s activity. A quiet week on the Sun as a cluster of active regions move across the Sun’s disk and around the limb. As of Friday, Sept. 18, there are no active regions on the Earth-facing side of the Sun. The dark “strips” across the Sun that emerge towards the end of the video are coronal holes. These cooler bands of solar material on the Sun (which make them appear darker) are where the Sun’s magnetic field lines open up to space, allowing high-speed solar wind to escape. More about solar activity and space weather:

2026.09.20 16:00

It’s #SunDay#! Here’s your space weather report for the week of Sept. 11 - Sept. 17: • 0 M-class flares • 0 C-class flares (only counted if associated with coronal mass ejections) • 17 coronal mass ejections • 0 geomagnetic storms This video from NASA’s Solar Dynamics Observatory shows the week’s activity. A quiet week on the Sun as a cluster of active regions move across the Sun’s disk and around the limb. As of Friday, Sept. 18, there are no active regions on the Earth-facing side of the Sun. The dark “strips” across the Sun that emerge towards the end of the video are coronal holes. These cooler bands of solar material on the Sun (which make them appear darker) are where the Sun’s magnetic field lines open up to space, allowing high-speed solar wind to escape. More about solar activity and space weather: