"We've
never seen anything quite like it," says solar physicist Lika Guhathakurta
from NASA headquarters.
Last week she
sat in an audience of nearly two hundred colleagues at the workshop in Boulder, Colorado, and watched in amazement as Saku Tsuneta of Japan played a movie of
sunspot 10926 breaking through the turbulent surface of the sun. Before their
very eyes an object as big as a planet materialized, and no one was prepared
for the form it took.
"It
looks like a prehistoric trilobite," said Marc De Rosa, a scientist from
Lockheed Martin's Solar and Astrophysics Laboratory in Palo Alto, Calif. "To me it seemed more like cellular mitosis in which duplicated chromosomes
self-assemble into two daughter cells," countered Guhathakurta.
"This movie is a magnetogram—a dynamic map tracing
the sunspot's intense magnetism," Guhathakurta explains. "Black
represents negative (S) polarity, and white represents positive (N)."
The data were gathered by the Japanese Space Agency's
Hinode spacecraft, launched in Sept. 2006 on a mission to study sunspots and
solar storms. "This is the highest resolution magnetogram ever taken from
space," says Tsuneta, Hinode's chief scientist at the National
Astronomical Observatory of Japan in Tokyo. "It's showing us things we've
never seen before."
Magnetograms are the best way to study sunspots. Why?
Although sunspots may appear solid and sturdy, they are not made of matter.
Sunspots are planet-sized knots of magnetism created by the sun's inner dynamo.
Born in the depths, they bob to the solar surface where they can shift, merge,
split and even appear to "swim."
"Sometimes the shifting and merging gets out of
hand," says Guhathakurta. "Magnetic fields become unstable and
explode, producing a powerful solar flare." The effects are manifold:
flares can disrupt communications on Earth, disable satellites, threaten
astronauts with deadly radiation storms and (on the bright side) trigger lovely
aurora borealis--the Northern Lights. Although researchers have been studying
flares for more than a century, they still cannot issue accurate flare
forecasts--something astronauts in orbit or en route to the Moon would dearly
love to have. Improving this situation is a key goal of the Hinode mission.
Participants at the Living With A Star workshop were
amazed by the quality of Hinode's data. "The sensitivity of Hinode's Solar
Optical Telescope is much higher than anything we've ever launched before. This
allows Hinode to detect even the very faintest magnetic fields." By
watching the ebb and flow of magnetism and the surprising forms that emerge,
"we hope to understand the behavior of sunspots and predict their
eruptions."
But first they've got to deal with the trilobites.
"We have a lot of work to do," says Guhathakurta. "But what a
wonderful problem."
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