We have investigated, and determined that these are artifacts caused by an interaction between the high compression factors used for the beacon data, and cosmic ray events on the detector. Our discussion of image artifacts has been updated to include this phenomenon. Another factor which has contributed to this issue has been the recent delay in receiving the full resolution images from the spacecraft. This was caused by a server problem at the Deep Space Network, and has now been resolved.

The twin STEREO spacecraft confirmed their reality in February 2009 when sunspot 11012 unexpectedly erupted. The blast hurled a billion-ton cloud of gas (a coronal mass ejection, or CME) into space and sent a tsunami racing along the sun's surface. STEREO recorded the wave from two positions separated by 90 degrees, giving researchers an unprecedented view of the event.