Our only close-up of Uranus was distorted by freak solar weather
By Jamie M. Jasinsk et al, Nature Astronomy.
Summary:
A human spacecraft has only gotten close to Uranus once—in 1986, when Voyager 2 drifted past the distant planet. That flyby indicated that Uranus was weird in several ways, which astronomers have spent decades trying to explain. Now, a new analysis in Nature Astronomy suggests the probe just happened to arrive there on an off day.
Voyager 2’s data indicated that Uranus had an “unusually oblique and off-centered magnetic field” with inexplicably intense electron radiation belts and a severely plasma-depleted magnetosphere,” the team behind the new work writes. But by mining old data from the mission, the scientists found evidence for a super strong solar wind that likely squished the magnetosphere just prior to the probe’s readings. This would have pushed any plasma too close to the planet to detect, and filled the radiation belts with high-energy particles.
Voyager 2’s data indicated that Uranus had an “unusually oblique and off-centered magnetic field” with inexplicably intense electron radiation belts and a severely plasma-depleted magnetosphere,” the team behind the new work writes. But by mining old data from the mission, the scientists found evidence for a super strong solar wind that likely squished the magnetosphere just prior to the probe’s readings. This would have pushed any plasma too close to the planet to detect, and filled the radiation belts with high-energy particles.
See also New York Times article
Uranus Might Have Experienced a Freak Event When Voyager 2 Visited