![]() Coronal Mass Ejections
Large flares are often associated with huge ejections of mass from the Sun, although the association is not clear. These coronal mass ejections (CMEs) are 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. The super-heated electrons from CMEs move along the magnetic field lines faster than the solar wind can flow. Rearrangement of the magnetic field, and solar flares may result in the formation of a shock that accelerates particles ahead of the CME loop. 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. Solar flares and CMEs are currently the biggest "explosions" in our solar system, roughly approaching the power in ONE BILLION hydrogen bombs!
Click on the image to see a movie of a CME from SOHO/LASCO of an April 7, 1997 halo CME event. A "halo" event is one where the CME is headed in the direction of Earth. The dark disk in the center is not the Sun, but the occulting, or Sun-blocking, disk of the LASCO coronagraph.
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This file was last modified:
May 21, 2009
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