An astonishing flip-flop on Uranus—report

Press, 30 July 1986, Page 51

An astonishing flip-flop on Uranus—report

NZPA-AP Pasadena The Voyager 2 spacecraft’s study of Uranus suggests the planet’s magnetic field might be reversing, an astonishing flip-flop in magnetic north and south poles never before witnessed, N.A.S.A. says.

“What we may be seeing is a magnetic field in the process of flipping,” said Ellis Miner, deputy Voyager project scientist at the National Aeronautics and Space Administrations jet propulsion laboratory. “While seafloor rocks show Earth’s magnetic field reversed at least nine times during the past 3i/j million years, most recently 730,000 years ago, humans have never witnessed a field reversal on any planet,” said Mario Acuna, an astrophysicist at N.A.S.A.’s Goddard Space Flight Centre in Greenbelt, Maryland.

Messrs Miner and Acuna emphasised that a flip-flop in Uranus’ magnetic field is only one possible explanation for bizarre observations made by Voyager when the spacecraft flew past the seventh planet from the Sun in January. Another, previously debated theory is that the planet’s strange magnetic field was created as an indirect result of an Earth-sized object crashing into Uranus and tipping it on its side early in the solar system’s history. Understanding Uranus’ magnetic field was important because it helped scientists learn about Earth’s magnetic field, which allows compass navigation, keeps out harmful radiation, and possibly affects climate, said David Stevenson, a planetary scientist at the California Institute of Technology.