On July 23, 2012, a massive cloud of solar material erupted off the sun's right side, zooming out into space, as seen by STEREO.
On July 23, 2012, a massive cloud of solar material erupted off the sun’s right side, zooming out into space. It soon passed one of NASA’s Solar Terrestrial Relations Observatory, or STEREO, spacecraft, which clocked the CME as traveling between 1,800 and 2,200 miles per second as it left the sun. This was the fastest CME ever observed by STEREO.
STEREO’s unique viewpoint from the sides of the sun plus data from NASA’s Solar Dynamics Observatory and the joint European Space Agency/NASA Solar and Heliospheric Observatory, helped scientists create models of the entire July 2012 event. They learned that an earlier, smaller CME helped clear the path for the larger event, thus contributing to its unusual speed.Credit: NASA/STEREO