Spacecraft Trio Peeks at Secret Recipe for Stormy Solar Weather

A three-spacecraft collaboration recorded for the first time the entire initiation process of a high-speed eruption of electrified gas from the Sun, providing clues about the Sun's secret recipe for stormy weather. The April 21, 2002 observation confirmed the predominant scenario for how these eruptions, called Coronal Mass Ejections, are blasted from the Sun.

CME observed by LASCO C2 --A false-color image sequence over two hours of a large coronal mass ejection 20 March 2000 taken by the LASCO C2 instrument. In this sequence a CME blasts into space a billion tons of particles traveling millions of miles an hour.

The three spacecraft involved were NASA's Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), which takes pictures of flaring regions using the Sun's high-energy X-rays and gamma rays; NASA's Transition Region and Coronal Explorer (TRACE), which makes images using ultraviolet light from the Sun; and the Solar and Heliospheric Observatory (SOHO) spacecraft, a collaboration between NASA and the European Space Agency.

"This was the first time that we have been able to identify and study in detail the region on the Sun where the initiation and acceleration of a coronal mass ejection occurs," said Dr. Peter Gallagher, research scientist for RHESSI and SOHO at Goddard and lead author of two papers on this research. "We now have a better understanding of how the energy release above the surface of the Sun relates to the ejection of material, perhaps allowing some real-time forecasts." The results are being presented today during a meeting of the American Astronomical Society's Solar Physics Division in a press conference at the Johns Hopkins University Applied Physics Laboratory, Laurel, Md.

Coronal Mass Ejections (CME) are often associated with solar flares. A flare is a giant explosion in the solar atmosphere that spews radiation and results in the heating of solar gas and the acceleration of particles to nearly the speed of light. Both events can be initiated in a matter of seconds, making their joint observations difficult to coordinate.

For more on the recording of the solar gas ejection from three spacecraft, go to: http://www.gsfc.nasa.gov/topstory/2003/0617rhessicme.html