Farside Watch for September 25, 2021.

The imagery below is provided by the STEREO Ahead spacecraft. It offers a partial look at the backside (farside) of the Sun opposite of Earth, including the section that rotates onto the Earth facing east limb. The mission did also include the STEREO-Behind spacecraft to provide a wider look at the farside, however communications were lost in October 2014 due to multiple hardware anomalies.

On average it takes 13.5 days for a region to transit the farside of the Sun. The rotation rate is faster towards the equator and slower towards the polar regions.

Possible new magnetic or spotted regions will appear in a white square.
Likely sunspots or returning active regions will appear in a red square.
CH = Coronal Hole.

Regions expected to return onto visible disk

Days until return
Still Active?

Where is STEREO-Ahead?


STEREO Website | Home