NASAVoyager 2’s 1986 flyby provided the only close-up glimpse of Uranus. Nearly 40 years later, scientists examine this data and discover that the visit took place during a strange space weather event.

Uranus is still a strange object, rotating sideways and taking 84 years to orbit the Sun. But Voyager’s flyby made Uranus a solar system outlier when spacecraft showed the planet had a magnetic field almost devoid of plasma and nothing to power the electron radiation belts.

Voyager’s visit was simply bad timing for Uranus, according to a new study.

The scientists published their results this week after reexamining the 38-year-old flyby data and discovering that just days before the flyby, a dense slap of plasma from the Sun had reached and “crushed” the planet’s magnetospheres in a rare space weather event.

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The suppressed magnetosphere was a surprise because the electron radiation belts were intense – just behind Jupiter in the solar system, according to NASA.

The study authors say this oddity was likely created by solar energy. winda space weather event in which plasma from the Sun chased plasma from the Uranus system.

“Such compression of the magnetosphere could increase energetic electron fluxes in the radiation belts and temporarily empty the magnetosphere of its plasma,” write the study authors. “Therefore, the interpretation of Uranus’ magnetosphere as extreme could simply be the product of a flyby occurring under extreme upstream solar wind conditions.”

If Voyager 2 had flown by Uranus a few days earlier or later, the planet’s magnetosphere would have been different. According to the study, these conditions likely only existed at the time of the flyover.

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Linda Spilker, Voyager 2 project scientist, said the new analysis “will once again change our view of Uranus.”

A mission to Uranus is considered a high priority for space agencies in the coming decades. NASA plans to explore a possible flagship mission, including an orbiter to Uranus and a probe dropped into the atmosphere in the next decade.

Original article source: Uranus is not as strange as scientists thought; it took almost 40 years to discover why