A spacecraft in solar orbit reached almost directly above the south pole of the Sun last week, giving scientists a rare glimpse of this unfamiliar territory. Launched on October 6, 1990, Ulysses, a joint mission of NASA and the European Space Agency, has made only two flybys of the south pole of the Sun. "The sun's south pole is uncharted territory," said Ulysses Program Scientist Arik Posner of NASA headquarters. "We can barely see it from Earth, and most of our sun-studying spacecraft are stationed over the sun's equator with a poor view of higher latitudes."The duration of the spacecraft's south polar pass is roughly four months. Last Thursday was the day of Ulysses' closest approach to that solar region. The spacecraft hasn’t spent enough time at the sun's high latitudes to really take in all the solar secrets that can be revealed from that point of view, Posner said. “We are trying to get all the information that we can get from these flybys,” he said. For more than 15 years, Ulysses has been collecting data that has led to a better understanding of the Sun's environment, which could also help scientists understand Earth better. "Both the sun's and Earth's magnetic poles are constantly on the move, and they occasionally do a complete flip, with N and S changing places," Posner said. This flipping happens every 11 years on the Sun, in synch with the sunspot cycle. It happens every 300,000 years or so on Earth, but no one knows what the Earth’s cycle corresponds with.
View: Full Article | Source: Space.com