Ulysses spacecraft - a joint mission of ASA and the European Space Agency, is making a rare flyby of the uns North Pole, from where it would be able to collect sample inds that may lead to new insights about solar activity.
Washington, Jan 15 : Ulysses spacecraft - a joint mission of ASA and the European Space Agency, is making a rare flyby of the un's North Pole, from where it would be able to collect sample inds that may lead to new insights about solar activity.
Solar physicists have already announced the first indications of new solar cycle, which makes this flyby all the more ignificant.
"This is a wonderful opportunity to examine the sun's north pole ithin a transition of cycles," said Arik Posner, Ulysses program cientist at NASA Headquarters in Washington. "We've never done his before," he added.
Many researchers believe the sun's poles are central to the 11-ear ebb and flow of solar activity.
First of all, when sunspots break up, their decaying magnetic ields are carried poleward by vast currents of plasma. This akes the poles a sort of graveyard for sunspots.
Also, old magnetic fields sink beneath the polar surface 200,000 ilometers deep, all the way down to the sun's inner magnetic ynamo, which generates the solar magnetic field. There, dynamo ction amplifies the fields for use in future solar cycles.
"Just as Earth's poles are crucial to studies of terrestrial limate change, the sun's poles may be crucial to studies of the olar cycle," said Ed Smith, Ulysses project scientist at NASA's et Propulsion Laboratory, Pasadena, California.
Each previous flyby has revealed something interesting and ysterious.
For example, Ulysses discovered the sun's high-speed polar wind. t the sun's poles, the magnetic field opens up and allows solar tmosphere to stream out at a million miles per hour. By flying round the sun, covering all latitudes in a way that no other pacecraft can, Ulysses has been able to monitor this polar wind hroughout the solar cycle and has found that it is acting a bit dd.
"Twelve years ago, just before the previous 'sea change' between olar cycles, the polar wind spilled down almost all the way to he sun's equator. But this time it is not The polar wind is ottled up, confined to latitudes above 45 degrees, " said osner.
Another puzzle has been the temperature of the sun's poles. In he previous solar cycle, the magnetic north pole was more than 4,000 degrees Celsius, or 8 percent cooler than the south. The urrent flyby may help solve this puzzle by comparing temperature easurements, north versus south, with hardly any gap between hem.
Ulysses has flown over the sun's poles three times before, in 994-95, 2000-01 and 2007.
ANI