Colorful auroras spread across Canada and some northern US states Friday night when the interplanetary magnetic field (IMF) near Earth unexpectedly tilted south, sparking a geomagnetic storm.
Image Left: A view of the aurora australis as taken by the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) spacecraft on Jan. 7. Click on the image for large quiktime, here for print resolution still, or watch a smaller mpg version. Credit: NASA. Image Right: A view from the ground taken in Marquette, Mich. Credit: Brian and Shawn Malone.
The movie shows about three hours of imagery of the aurora Australis taken from the IMAGE spacecraft late in the UT day of Fri. 7 Jan 2005 (16:00 to 19:00 EST). During this period, there was a significant auroral - geospace storm. The viewpoint is looking generally toward the sun but a bit toward the north and west (sun to the lower right off the image).
The coronal mass ejection (CME) that sent plasma hurtling toward space erupted Jan. 9 from the sunspot designated Active Region 719. Another CME blew off the Sun just one week earlier, within the first few minutes of 2005. Click here to check out the active regions on the Sun today.
The aurora, also known as the Northern and Southern Lights, form when solar particles and magnetic fields pump energy into the Earth's magnetic field, accelerating electrically charged particles trapped within. The high-speed particles crash into Earth's upper atmosphere (ionosphere) over the polar regions, causing the atmosphere to emit a ghostly, multicolored glow. A few small active regions are rotating around the Sun this week, but no major flares or CMEs are expected.
Dramatic solar activity is getting increasingly rare as we enter into the quiet period of the Sun's eleven-year cycle of activity. The years 2000-2001 marked the highest point of activity, but that doesn't preclude the occasional surprise like last week's CMEs. Even more significant were the intense solar storms that raged about a year ago.
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Rachel A. Weintraub
NASA Goddard Space Flight Center