NASA has already released a video of the Sun as seen by the SOHO spacecraft, including the vast region that has gone dark.
Coronal holes are darker and cooler regions of the Sun’s atmosphere, containing little solar material. They can affect space weather, since they send solar particles streaming off the Sun about three times faster than the wind unleashed anywhere else in its atmosphere, as NASA says.
“While it’s unclear what causes coronal holes, they correlate to areas on the sun where magnetic fields soar up and away, failing to loop back down to the surface, as they do elsewhere,” a NASA employee said.
The activity is viewed as odd since coronal holes usually decrease leading up to the magnetic pole switch that happens around solar maximum, the Sun’s activity peak, which is currently taking place.
- Why is a Huge Chunk of the Sun Missing? (blogs.discovermagazine.com)