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23-01-09 NASA Sees Far Side of the Sun

NASA's twin STEREO spacecraft are offering the first glimpse of the far side of the sun,the space agency announced today.The two spacecraft,launched Oct. 25, 2006,are beaming back over-the-horizon images "that have researchers and forecasters glued to their monitors,"according to a statement."This is a perspective we've never had before,"says STEREO mission scientist Lika Guhathakurta of NASA headquarters."We're now monitoring more than 270 degrees of solar longitude - that's 3/4ths of the star." Just in time.Because the sun rotates,all of it is seen from Earth over time.But at any given time,only half of the star is visible.Scientists who monitor solar eruptions and the space storms they hurl toward Earth are eager to monitor the whole star 24/7.Seeing storms on the far side,which is of course just as bright and active as the near side,would improve forecasting abilities."After all these years,"Guhathakurta quipped,"we're finally getting to see the dark side of the sun."Since the two STEREO spacecraft went into orbit around the sun at the beginning of 2007,they have been slowly drifting apart from Earth,and from each other.They are now 90 degrees apart.They will be in their final positions on Feb. 6,2011,hovering 180 degrees apart and imaging the entire sun all the time.That timing will match with the next expected peak in solar activity.The sun is at a low point in it's 11-year cycle of activity now.But over the next few years,sunspots will become more common and flares more frequent.The peak will likely occur in 2012.