Ever thought about those emissions from our star and wondered how sun spots develop? Well, Michael Knölker, director of the High Altitude Observatory at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, is thinking about this a lot. So much so, that he has developed an interesting way for us to get out of our own atmosphere to take an ultraviolet view of Sol.
Knölker has developed a high altitude balloon to transport the largest solar, ultraviolet telescope up into the stratosphere at 37 km high.
The Sunrise project, a 1-metre solar UV telescope, will be transported to where our atmosphere has little effect on the Ultraviolet band of the light spectrum. Ultraviolet observations cannot be done from the Earth's surface, since the same UV-absorbing properties that make ozone so beneficial to life also block the light from reaching ground-based telescopes. The telescope would be able to image features on the Sun as small as 30 kilometres across, more than double the resolution of other instruments. That is thought to be the size of the smallest features so far observed on the Sun's surface – bright structures called flux tubes.
"They are key to the evolution of magnetic fields [that can lead to] solar eruptions of magnetised plasma that – when it reaches the Earth – can cause a geomagnetic storm and disrupt satellites," says Knölker. "We are confident that if we can resolve, say 30 kilometres, we will be learning something very substantial [about the flux tubes]." he adds.
Magnetic Flux Tubes are of interest because of their close relation to their much larger cousins: Sun Spots. By modeling MFT's it is hoped that more can be learned about Sun Spots. Sun Spots are much larger and longer lived. They are the single biggest influence on the amount of solar radiation that reaches the earth, and can have tremendous impact on radio communications, and the thickness of the earth's atmosphere. When sun spots are active they cause heating in the upper atmosphere, which in turn causes expansion. Skylab fell to earth prematurely in 1979 due to this phenomenon when an unexpected Sun Spot flared up. The launch of the Hubble telescope was delayed for a year because of Sun Spot activity.
The Sunrise telescope is expected to be ready to make its first scientific observations in mid-2009. Then, organisers hope to take advantage of the 'midnight Sun' to send it on a flight around the Arctic lasting as long as two weeks (though this is dependent on Russia relaxing its current ban on US balloons flying in its airspace).
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