At one point, as a solar prominence erupted into space, it seemed to create the Greek letter Pi as seen by SDO on July 4, 2015.
At one point, as a solar prominence erupted into space, it seemed to create the Greek letter Pi as seen by NASA’s Solar Dynamics Observatory, or SDO, on July 4, 2015. Pi is the symbol for the ratio of a circle’s circumference. Prominences, which are elongated clouds of plasma suspended above the sun’s surface by magnetic forces, frequently become unstable and erupt. This one did blow a cloud of particles into space as observed by the ESA&NASA SOHO spacecraft, though our close-up shows that some of it fell back into the sun. The video clip covers about seven hours of activity in 304 wavelength of extreme ultraviolet light. Credit: NASA/SDO/Steele Hill