NASA - Solar Dynamics Observatory (SDO) patch.
May 1, 2013
Circular Coronal Mass Ejection
A coronal mass ejection (CME) erupted from just around the edge of the sun on May 1, 2013, in a gigantic rolling wave. CMEs can shoot over a billion tons of particles into space at over a million miles per hour. This CME occurred on the sun’s limb and is not headed toward Earth. The video, taken in extreme ultraviolet light by NASA’s Solar Dynamics Observatory (SDO), covers about two and a half hours. Credit: NASA/SDO.
What is a solar prominence?
A solar prominence (also known as a filament when viewed against the solar disk) is a large, bright feature extending outward from the Sun's surface. Prominences are anchored to the Sun's surface in the photosphere, and extend outwards into the Sun's hot outer atmosphere, called the corona. A prominence forms over timescales of about a day, and stable prominences may persist in the corona for several months, looping hundreds of thousands of miles into space. Scientists are still researching how and why prominences are formed.
The red-glowing looped material is plasma, a hot gas comprised of electrically charged hydrogen and helium. The prominence plasma flows along a tangled and twisted structure of magnetic fields generated by the sun’s internal dynamo. An erupting prominence occurs when such a structure becomes unstable and bursts outward, releasing the plasma.
Image above: A solar eruptive prominence as seen in extreme UV light on March 30, 2010 with Earth superimposed for a sense of scale. Credit: NASA/SDO.
What is a coronal mass ejection or CME?
The outer solar atmosphere, the corona, is structured by strong magnetic fields. Where these fields are closed, often above sunspot groups, the confined solar atmosphere can suddenly and violently release bubbles of gas and magnetic fields called coronal mass ejections. A large CME can contain a billion tons of matter that can be accelerated to several million miles per hour in a spectacular explosion. Solar material streams out through the interplanetary medium, impacting any planet or spacecraft in its path. CMEs are sometimes associated with flares but can occur independently.
For answers to these and other space weather questions, please visit the Spaceweather Frequently Asked Questions page: http://www.nasa.gov/mission_pages/sunearth/spaceweather/index.html
Images, Video, Text, Credits: NASA / SDO.
