A large solar flare gives rise to humongous waves on the sun.
On March 6, 2012, giant waves known as "solar tsunamis" swept across the sun just after an eruption of an X5.4-class flare, the second largest solar flare since 2006. NASA's Solar Dynamics Observatory (SDO) satellite mapped the evolution of the waves—some stretching across the entire 865,000-mile width of the sun—as they rippled outward from the flare at speeds greater than one million miles per hour. These waves, officially called "EIT waves," may be what triggers fast coronal mass ejections, the spectacular clouds of ejected solar material that sometimes follow a flare, achieve escape velocity and hurtle into space. The video below shows two distinct waves emerging after the flare: the first spreads in all directions; the second is narrower, moving toward the southeast. It is likely that both are connected to one of the two coronal mass ejections spotted about an hour and a half after the eruption.