Spotlight on the sun

Science World, Feb 18, 2008 by Jeanna Bryner

Last fall, an air balloon the size of a jumbo jet carried a solar telescope high above Earth. The unmanned balloon snapped photos of the sun during a 10-hour test flight over the South Pole.

In the summer of 2009, scientists hope to launch the balloon again--this time above the North Pole. The project, called Sunrise, aims to learn more about the sun's surface and its magnetic field.

"One of our goals is to look at the smallest structures we can resolve on the surface of the sun," says Michael Knolker, lead scientist on the Sunrise project at the National Center for Atmospheric Research in Colorado. For instance, tube-shape structures extend from the sun's surface like giant loops. Knolker says the electromagnetic force surrounding the sun fuels these flux tubes.

In order to collect the clearest photos of this phenomenon, scientists will launch the telescope-equipped balloon to an altitude of 40 kilometers (25 miles). Way up there, the telescope will be over Earth's lower atmosphere, above where water vapor and clouds can blur images.

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