#ERUPTION: Yesterday, astronomers in Europe witnessed the most spectacular eruption of #Solar Cycle 25 so far. "It was a spine-chilling moment for me," says Mehmet Ergün, who photographed the massive spray of plasma from his observatory in Traisen, #Germany:

"This was probably the biggest eruption I have ever seen," says Ergün. "Such events cannot be planned. I was lucky to be looking when it happened."

Many observers noted the rapidity of the blast. Giorgio Rizzarelli of Trieste, #Italy, says "it lasted only about one hour. Fast prominences like this are uncommon. From a movie I made I estimate its speed was comparable to that of the solar wind." Dennis Put of The #Netherlands says "it was changing so rapidly, which made it very spectacular."

NASA's Solar Dynamics Observatory captured a beginning-to-end movie of the blast:

What exploded? We don't know. The blast site is hidden behind the sun's southeastern limb. Helioseismic maps of the #sun's farside suggest a large #sunspot may be located at the base of the spray.