Images from the TRACE spacecreaft of electrifyied gas streams loops

Hypervelocity Winds Rage in the Sun's Atmosphere

Winds of electrified gas rip through the solar atmosphere at nearly the speed of sound there, according to new observations from NASA's Transition Region and Coronal Explorer (TRACE) spacecraft and the European Space Agency/NASA Solar and Heliospheric Observatory (SOHO) spacecraft.

The new result, from a team of astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass., shows that the winds and storms of the solar atmosphere -- at speeds up to 200,000 miles per hour -- so intense that they are more important than gravity in determining the density of the atmosphere. The Sun's gravity at its visible surface is about 28 times stronger than that at the Earth's surface; a 150-pound person would face an epic struggle to support 4,200 pounds if he or she could somehow stand on the solar surface. For the Earth's atmosphere to behave similarly, winds over 3,000 mph would be common on the surface.

"This discovery completely changes our understanding of coronal loops, immense, arch-shaped structures of electrified gas that comprise the Sun's outer atmosphere (corona)," said Amy Winebarger, lead author of a paper on this research published in March in the Astrophysical Journal. "We are excited about this because it increases our understanding of the corona, which is the location of explosive solar activity that occasionally disrupts high-technology systems at Earth." Winebarger, formerly at CfA, is a solar physicist for Computational Physics Incorporated, Springfield, Va., and is now with the Naval Research Laboratory in Washington.

For more info on the solar winds, go to: http://www.gsfc.nasa.gov/topstory/20020515tracewind.htm