NASA has released additional images captured during a massive coronal mass ejection (CME) in July 2012, some of which clearly show the formation of CMEs — a first for astronomers.
The images, which allowed astronomers to confirm that flux ropes — long strands of magnetic energy — precede the formation of CMEs, are the first captured by the space agency. The images are widely seen as some of the most important captured of the sun and could help astronomers better predict when the sun will eject CMEs and when they will strike Earth.
CEMs are caused when the strong magnetic fields found in the outer solar atmosphere are twisted and braided. When the magnetic loops are rearranged, solar flares or CMEs may eject balloon-shaped bursts of solar wind rising above the solar corona, expanding as they climb. Solar plasma is heated to tens of millions of degrees, and electrons, protons, and heavy nuclei are accelerated to near the speed of light, often spewing outwards towards Earth. According to NASA, each CME releases up to 100 billion kg (220 billion lb) of this material, and the speed of the ejection can reach 1000 km/second (2 million mph) in some flares.
The pattern captured in the images allows astronomers to better understand the evolution of the sun’s environment. Astronomers had long suspected that flux rope as magnetic field lines in the Sun’s corona began to twist about, generating a coil of the hottest material on the Sun, which then resulted in CMEs. However, until now the theory was largely unproven. Past images had captured the flux ropes in action, but scientists said they were unable to obtain detailed images that proved the theory.
While the images are seen as a massive accomplishment for the space agency, it remains unclear why NASA kept the images from the public for so long. The space agency noted that it did indeed capture the images during the summer of 2012, but it was not noted what was done with the images since then. A number of astronomers suggested the images were studied by NASA scientists in an effort to confirm the flux rope finding.
The timing of the images, however, could not be better. The sun is currently in an active phase of its 11-year solar weather cycle and astronomers say they expect it to reach its peak activity period in 2013. The images were captured by the Atmospheric Imaging Assembly (AIA) instrument on board NASA’s Solar Dynamics Observatory (SDO).