THE JOKES PRACTICALLY WRITE THEMSELVES.

Wind Blowing Out of Uranus Makes It Hard to Probe.  No, that's not scatological humor incoming, rather, it's bad luck, with a solar flare travelling much faster than Voyager hitting Uranus about when Voyager passed.

[Jet Propulsion Laboratory scientist Jamie] Jasinksi reexamined the data collected by Voyager 2 during its 1986 flyby and found that the probe had examined Uranus shortly after an intense solar wind event, which saw a huge surge of charged particles blast its way from the Sun.

The event compressed the planet's magnetosphere, they found, causing it to deform into a significantly asymmetrical shape that appeared to lack plasma.

"We postulate that such a compression of the magnetosphere could increase energetic electron fluxes within the radiation belts and empty the magnetosphere of its plasma temporarily," the researchers wrote in their paper.

Even if Voyager 2 had come to visit a mere week earlier, the researchers suggest, it would have found a far more recognizable magnetosphere, like those surrounding other planets in our solar system, including Jupiter, Saturn, and Neptune.

"Owing to the variation of the solar wind at Uranus, we suggest that there may be two magnetospheric cycles during solar minimum," the researchers suggested, referring to the calmest period of the Sun's 11-year solar cycle.

Intriguingly, Uranus' two most distant moons Titania and Oberon may be orbiting the planet outside the magnetosphere, which could give astronomers an unprecedented look at their subsurface oceans without any electromagnetic interference.

In short, we shouldn't draw any definitive conclusions from NASA's flyby almost 40 years ago.

I wonder if the auroras were spectacular, or if ionized particles require some sort of atmosphere.  It's not, though, as if there's a space probe standing by to do a Uranian fly-by in the next year or so, or if their luck avoiding a solar storm would be any better.

If I recall correctly, the two early Voyagers took advantage of alignments of the outer planets that made fly-bys of all of them practicable.  Thanks to the long orbits, those alignments are rare.