Something Strange Happened During Voyager 2’s Flyby of Uranus in 1986

A caller investigation of 38-year-old Voyager 2 information indicates that the intrepid spacecraft flew past Uranus astatine an antithetic infinitesimal erstwhile the planet’s magnetosphere was warped by particles from the Sun.

The research—published contiguous successful Nature Astronomy—suggests that the magnetic operation of the Uranian strategy is antithetic than initially thought. Initial investigation of the Voyager 2 information suggested that the planet’s magnetosphere—the country astir Uranus dominated by its magnetic field—was devoid of plasma, which is contiguous successful different planetary magnetospheres.

The information besides indicated that the Uranian magnetosphere had aggravated belts of energetic electrons, dissimilar that of different planets. Besides being the butt of truthful galore jokes, Uranus’ environs appeared to beryllium bizarre compared to the remainder of our star system.

The scientists down the updated probe posit that these antithetic circumstances were really the effect of an aggravated blast of star wind—charged particles from the Sun’s atmosphere—which warped the magnetosphere conscionable arsenic Voyager 2 flew past successful 1986.

“These were 2 large mysteries leftover from the Voyager 2 flyby, some of which tin beryllium reasonably explained by the accomplishment of an aggravated star upwind lawsuit that compressed the magnetosphere dramatically conscionable earlier the flyby started,” said Jamie Jasinski, a planetary idiosyncratic astatine NASA’s Jet Propulsion Laboratory and Caltech, and the study’s pb author, successful an email to Gizmodo.

“If we had arrived a week earlier with Voyager 2 past the spacecraft would person made wholly antithetic measurements, and our discoveries would person been precise different,” Jasinski said. “Voyager 2 arrived astatine conscionable the incorrect time!”

The uncommon compression of the magnetosphere lone occurs 4% of the clip astir Uranus, according to the team’s estimates. The different 96% of the time, the planet’s magnetosphere isn’t truthful extreme. The findings besides suggest that during the star minimum—the debased constituent of the Sun’s 11-year cycle—Uranus experiences alternating periods of disturbed star upwind that impact its magnetosphere. The cycles during which the magnetosphere is “open” oregon “closed” to the star upwind whitethorn beryllium owed to Uranus’ tilt, which is utmost relative to the star system’s orbital plane.

Based connected the Voyager 2 data, the squad concluded that “the Uranian magnetosphere whitethorn good person had 2 cycles astatine the clip of the Voyager 2 flyby: the archetypal varying connected a diurnal timescale owed to the ‘switch-like’ oregon ‘open-closed’ processes mentioned above, and the 2nd owed to the varying star upwind conditions.”

Voyager 2 is the lone spacecraft to sojourn Uranus and Neptune; it besides discovered 16 moons and six planetary rings arsenic it made its mode retired of our star system. Voyager 2 is now 47 years and 2 months into its mission, traveling done interstellar abstraction astatine 34,391 miles per hr (55,347 kilometers per hour). The ngo is astir 13 cardinal miles (20.9 cardinal kilometers) from Earth—over 138 times the region betwixt Earth and the Sun. Voyager 2 is truthful distant that it takes airy implicit 19 hours to question from the spacecraft to Earth.

Over the past 35 years, NASA enacted power-saving measures that person turned disconnected all but four of the Voyager spacecraft instruments: the 2 missions’ cosmic ray subsystems, magnetometers, and instruments for measuring charged particles and electrical fields stay operational.

“It’s an breathtaking work,” said Carol Paty, a planetologist astatine the University of Oregon who is not affiliated with the caller paper, successful a telephone telephone to Gizmodo. “It’s ever fantastic erstwhile you tin spell backmost to information that’s decades aged with caller eyes and caller perspective.”

As the caller survey suggests, Voyager 2 observed a peculiarly utmost lawsuit involving Uranus’ magnetosphere, but Paty noted that it would beryllium a measurement excessively acold to presume the state giant’s emblematic authorities is akin to that of different planets successful our star system. Uranus’ magnetosphere is inactive precise asymmetric, and the space of the planet’s rotation inactive means that it has immoderate of the astir utmost seasons of immoderate satellite successful the star system.

“What we cognize from looking astatine this paper, conscionable from the upstream star upwind information investigation alone, the star upwind is rather adaptable adjacent retired astatine the orbital region of Uranus,” Paty said. “And that variability means that this strategy is going to beryllium incredibly dynamic and responsive to the star wind.”

Uranus is an breathtaking venue for astrobiology—that’s beingness disconnected Earth, not biology successful your…never mind. In 2022, a 780-page study by the National Academies of Sciences, Engineering, and Medicine called for a Uranus orbiter susceptible of mapping the planet’s gravitational and magnetic fields and adjacent motorboat an atmospheric probe into its skies.

Separate from the report, planetary scientists person made akin arguments; Uranus has galore mysteries, and nary spacecraft has visited it since Voyager 2. The mission’s images of the satellite and its moons proceed to beryllium the main information connected which planetary scientists trust erstwhile producing caller probe astir Uranus, arsenic indicated by a insubstantial past week connected the anticipation of a subsurface water connected Miranda, 1 of the planet’s moons.

In the caller findings, the squad besides concluded that Uranus’ outermost moons, Titania and Oberon, orbit wrong the planet’s magnetosphere alternatively of extracurricular it. That would marque it overmuch easier for a spacecraft to find the beingness of a subsurface ocean, which it does by inducing a magnetic tract effect from the liquid h2o beneath the moon’s surface.

“Titania and Oberon are the astir apt candidates for harboring oceans due to the fact that they are somewhat larger than the different moons, meaning they tin clasp vigor better, and truthful beryllium warmer,” Jasinski said. “This means they are little apt to beryllium wholly frozen.” And based connected the team’s reappraisal of the Voyager data, those plausibly liquid contents of the moons would beryllium easier to observe than antecedently thought.

It’s precocious clip we got our asses to Uranus. But until then, scientists volition extract each past spot of penetration from the information cod by Voyager astir 40 years ago.