Ulysses makes a return trip.Just as the sun is reaching the stormy peak of its 11-year activity cycle, the European Space Agency's Ulysses spacecraft has begun its second pass over the sun's poles. Six years ago, when Ulysses completed its first polar swoop, the sun was at the minimum of its cycle and relatively quiescent quiescent at rest; latent; the G0 stage of the cell cycle. . Back then, Ulysses' measurements revealed that the solar wind--the stream of charged particles flowing out of the sun--was blowing at a rapid, steady rate of 750 kilometers per second at the poles. Today the solar wind solar wind, stream of ionized hydrogen—protons and electrons—with an 8% component of helium ions and trace amounts of heavier ions that radiates outward from the sun at high speeds. at the same high latitudes is more chaotic and blustery blus·ter v. blus·tered, blus·ter·ing, blus·ters v.intr. 1. To blow in loud, violent gusts, as the wind during a storm. 2. a. To speak in a loudly arrogant or bullying manner. . Ulysses crossed the solar latitude of 70 [degrees] S on Sept. 8 and will spend the next 4 months flying over the sun's south polar region South Polar Region See Polar Regions. . Then, after swinging back over the sun's equator, the craft will begin passing over the sun's northern polar area on Sept. 3, 2001. Ulysses is scheduled to complete its second and final trip around the sun in 2004. "By the time the mission comes to an end, Ulysses will have gathered the only set of observations above the solar poles covering more than a complete 11-year solar cycle solar cycle Period in which several important kinds of solar activity repeat, discovered in 1843 by Samuel Heinrich Schwabe (1789–1875). Lasting about 22 years on average, it includes two 11-year cycles of sunspots, whose magnetic polarities alternate between the ," says Ulysses scientist Andre Balogh of the Imperial College of Science, Technology, and Medicine in London. |
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