The second plenary talk of the day is on the topic of the Sun, and has the most distracting powerpoint backgrounds I have ever seen - beautiful movies from Hinode showing active regions on the solar surface. Our view of our parent star is being radically changed by a new generation of missions, including not just Hinode but also STEREO.

A particularly dramatic event is illustrated below in an image being unveiled today by David Long of Trinity College Dublin.

It shows a large wave - a tsunami, perhaps - moving across the Sun’s surface. Traveling at up to a million kilometers per hour, this shock wave was kick started by a coronal mass ejection. These dramatic events involve the ejection of material from the solar surface, although the details are - as whenever magnetic fields get involved in astronomy - complicated almost beyond belief. The close up view provided by STEREO in each of four wavelengths has proved equally confusing; each wavelength of light corresponds to different layers of the Sun’s atmosphere. The wave should pass more slowly in lower and denser atmospheric layers, but instead appears to move with the same speed wherever it’s observed. More mysteries - and more beautiful images - for solar physicists.