A few of Uranus’ obvious oddities could be on account of unhealthy timing.
In 1986, the Voyager 2 spacecraft flew previous the planet, recording mysteries of its magnetic area. Seems, Uranus might have simply been in an uncommon state. A photo voltaic wind occasion days earlier than the flyby compressed the giant planet’s magnetosphere, researchers report November 11 in Nature Astronomy. That compression might clarify a number of long-standing puzzles about Uranus and its moons, and will inform planning for future missions (SN: 4/20/22).
“We simply caught it at this freak second in time,” says Jamie Jasinski, an area plasma physicist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Should you had recognized that moving into, you’ll have questioned every part that Voyager 2 measured.”
Voyager 2 discovered that Uranus’ magnetosphere, the bubble of magnetism surrounding a planet, was weird. It appeared to lack plasma, a typical part of different planets’ magnetospheres. And it had inexplicably intense belts of energetic electrons.
Jasinski and colleagues seemed again at data Voyager 2 collected months earlier than the flyby (SN: 2/1/86). The staff discovered that the density and velocity of the photo voltaic wind, a stream of charged particles emanating from the solar, elevated steadily for days.
The stress from that photo voltaic wind would have compressed Uranus’ magnetosphere, shrinking its extent from an estimated 28 occasions Uranus’ diameter to extra like 17 occasions it inside per week. The compression might account for each the dearth of plasma and the extreme radiation belts, Jasinski says.
In truth, Uranus is within the state by which Voyager 2 discovered it solely 4 p.c of the time, the staff calculates. Meaning a lot of what we learn about Uranus’ magnetosphere doesn’t characterize a typical day there.
“We don’t actually know something about Uranus, as a result of it was a single flyby,” says Corey Cochrane, an area physicist additionally at JPL.
On the plus aspect, the brand new discovering means it could be simpler for some future mission to seek for oceans beneath the floor of Uranus’ moons Titania and Oberon.
Astronomers can detect oceans on icy moons in the event that they orbit contained in the magnetosphere (SN: 10/8/24). Salty water responds to the magnetic area round it and produces its personal magnetic area, which spacecraft can decide up. If Uranus’ magnetosphere is generally greater than documented by Voyager 2, these moons must be nicely inside it — and subsequently good websites to seek for subsurface seas.
Source link
