On June 7, 2011, Earth-orbiting satellites detected a flash of X-rays coming from the western edge of the solar disk. Registering only "M" (for medium) on the Richter scale of solar flares, the blast at first appeared to be a minor eruption until researchers studied the video images.

"We'd never seen anything like it," says Alex Young, a solar physicist at the Goddard Space Flight Center. "Half of the sun appeared to be blowing itself to bits."

NASA has just released new high-resolution videos of the event recorded by the Solar Dynamics Observatory (SDO). "In terms of raw power, this really was just a medium-sized eruption," says Young, "but it had a uniquely dramatic appearance caused by all the inky-dark material. We don't usually see that."

This 13 MB extreme ultraviolet movie of the explosion shows a 'solar tsunami' wave billowing away from the blast site. Solar physicist Angelos Vourlidas of the Naval Research Lab in Washington DC calls it a case of "dark fireworks. The blast was triggered by an unstable magnetic filament near the sun's surface," he explains. "That filament was loaded down with plasma, which exploded in a spray of dark blobs and streamers."

The plasma blobs were as big as planets, many larger than Earth. They rose and fell ballistically, moving under the influence of the sun's gravity like balls tossed in the air, exploding "like bombs" when they hit the stellar surface.

Some blobs, however, were more like guided missiles. "In the movies we can see material 'grabbed' by magnetic fields and funneled toward sunspot groups hundreds of thousands of kilometers away," notes Young.

SDO also detected a shadowy shock wave issuing from the blast site. The 'solar tsunami' propagated more than halfway across the sun, visibly shaking filaments and loops of magnetism along the way. "The June 7th blast didn't seem to trigger any big secondary explosions, but it was certainly felt far and wide," says Young.

"The blast also propelled a significant coronal mass ejection (CME) out of the sun's atmosphere," said Vourlidas. He estimates that the cloud massed about 4.5 x1015 grams, placing it in the top 5% of all CMEs recorded in the Space Age. For comparison, the most massive CME ever recorded was 1016 grams, only a factor of ~2 greater than the June 7th cloud.The amount of material that fell back to the sun on June 7th was approximately equal to the amount that flew away, Vourlidas says.

Before SDO, space-based observatories observed the sun with relatively slow cadences and/or limited fields of view. They could have easily missed the majesty of such an explosion, catching only a single off-center snapshot at the beginning or end of the blast to hint at what actually happened.