When the sun gets a little gassy, it sure puts on a grand display. NASA just released this footage of a coronal mass ejection (CME) bursting off the side of the sun, taken by its newest sun observer IRIS on May 9. CMEs are massive clouds of charged particles that are ejected by the sun over several hours. In this video, solar material is racing from the sun at speeds of about 1.5 million miles per hour. For perspective, the field of view is about five Earths wide and a little over seven Earths tall.
Sun Spotter
IRIS was launched in June 2013 to monitor the lowest levels of the sun’s atmosphere in high resolution, and this is the first CME captured by the instrument. Observing a CME is a tricky undertaking since scientists need to point IRIS in a specific direction at least a day in advance. The line moving across the middle of the video is the entrance slit for IRIS's spectrograph, an instrument that can split light into its many wavelengths. Scientists use this technique to measure temperature, velocity and density of the solar material behind the slit.
