NASA
26th February 2010, 19:53
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.
More... (http://stereo.gsfc.nasa.gov/news/SolarTsunami.shtml)
More... (http://stereo.gsfc.nasa.gov/news/SolarTsunami.shtml)