Solar cycle update – Ulysses visits pole - January 15, 2008
NASA is hailing a “a case of exquisite timing” as the Ulysses probe it runs with ESA flies over the Sun’s north pole just days after the start of a new solar cycle was confirmed.
“This is a wonderful opportunity to examine the Sun’s North Pole at the onset of a new solar cycle. We’ve never done this before,” says Arik Posner, Ulysses program scientist (press release).
NASA researchers think the poles could be vital to understanding the solar cycle, in part because when sunspots break up the decaying magnetic fields they leave behind end up at the poles. They hope to learn more about some previous, and strange, observations such as why the magnetic north pole was about 80,000 degrees cooler than the south during previous measurements.
This will be Ulysses’s fourth visit to the sun’s poles, having previously visited in 1994-95, 2000-01 and 2007. It has now long exceeded the voyaging of its Greek namesake, who was only travelling for a paltry ten years; it has also gone a fair bit further, voyaging out as far as Jupiter before swinging out of the ecliptic and back towards the sun,
“Each flyby revealed something interesting and mysterious, but this one may be most interesting of all,” says NASA (press release).
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Great Beyond post on new solar cycle
Image: artist impression of Ulysses / ESA