By Ron Cowen
The more things change, the more they stay the same. That old adage accurately describes the behavior of the solar magnetic field revealed by a new study. Waxing and waning, even flipping direction, the sun’s magnetic field undergoes dramatic upheavals yet always returns to its original shape and position.
“The sun’s magnetic field has a memory and [has returned] to approximately the same configuration” during each of the past three solar-activity cycles, says Marcia Neugebauer of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif. She and her JPL colleagues base their finding, described in the Feb. 1 Journal Of Geophysical Research, on an analysis of 250,000 hours of solar data compiled by spacecraft between 1960 and 1998.