Posted on 02/28/2025 12:48:01 PM PST by Red Badger
Research led by Burkhard Militzer, University of California Berkeley
This false color photograph of Neptune was made from Voyager 2 images taken through three filters: blue, green, and a filter that passes light at a wavelength that is absorbed by methane gas. (Credit: NASA/JPL)
In a nutshell
Uranus and Neptune have weird, disorganized magnetic fields because their interiors naturally separate into two distinct layers—a flowing water-rich upper layer and a stable hydrocarbon-rich lower layer.
Using advanced simulations of 540 atoms under extreme pressure and temperature, Berkeley physicist Burkhard Militzer discovered that planetary ices (water, methane, and ammonia) spontaneously separate rather than staying mixed.
This discovery could help us understand thousands of similar “ice giant” planets throughout the galaxy, which appear to be among the most common type of exoplanets discovered so far.
===============================================================================
BERKELEY, Calif. — For decades, something strange has lurked inside the icy giants of our solar system. Uranus and Neptune, distant blue worlds 1.7 billion miles from Earth, harbor magnetic fields that behave nothing like those of their planetary siblings. While Earth’s magnetic field resembles a bar magnet neatly aligned with its axis, these planets generate wonky, off-center fields that seemingly defy explanation, until now. A Berkeley physicist has cracked the case by revealing that their interiors naturally separate like oil and water, forever changing our understanding of these mysterious worlds.
Like Oil and Water, But in Space The research, published in the Proceedings of the National Academy of Sciences, was conducted by planetary scientist Burkhard Militzer from the University of California, Berkeley. He discovered that under extreme conditions inside ice giants, familiar compounds behave in surprising ways.
“We now have a good theory why Uranus and Neptune have really different fields, and it’s very different from Earth, Jupiter, and Saturn,” says Militzer, in a statement. “It’s like oil and water, except the oil goes below because hydrogen is lost.”
When scientists talk about “ices” in these planets, they don’t mean frozen water. In planetary science, “ices” refer to compounds that were frozen in the outer solar system when the planets formed, including water, methane, and ammonia. Inside Uranus and Neptune, these materials exist as hot, dense fluids under crushing pressure.
Previous theories suggested these materials would stay mixed throughout the planets’ interiors, creating uniform layers that should generate Earth-like magnetic fields. But that’s not what Voyager 2 observed.
Better Computer Models Militzer struggled with this problem for years. A decade ago, his computer simulations with about 100 atoms couldn’t show how layers might form under ice-giant conditions.
Last year, with more powerful computing and machine learning assistance, he ran simulations with 540 atoms that revealed something unexpected: the materials naturally separated into layers.
“One day, I looked at the model, and the water had separated from the carbon and nitrogen,” says Militzer. “I thought, ‘Wow! Now I know why the layers form: One is water-rich and the other is carbon-rich, and in Uranus and Neptune, it’s the carbon-rich system that is below.'”
Two Distinct Layers with Different Properties
Models for the interior structures of the ice-giant planets Uranus and Neptune have two distinct, intermediate layers: an upper, water-rich convecting layer where disorganized magnetic fields are generated, and a lower, non-convecting hydrocarbon-rich layer. New computer simulations show that icy materials naturally separate at high pressure and temperature into these two layers. (Credit: Burkhard Militzer, UC Berkeley)
The simulations showed planetary ices spontaneously separate into two layers: an upper layer rich in water and a lower layer dominated by carbon and nitrogen compounds. As pressure increases deeper in the planets, the lower layer releases hydrogen, creating a stable pattern where materials don’t mix vertically.
This layered structure explains the magnetic field mystery. The upper, water-rich layer flows and churns, creating the conditions needed to generate a magnetic field. Meanwhile, the lower layer remains still and stratified, preventing it from contributing to the magnetic field generation.
How Planetary Magnetic Fields Work
A planet’s magnetic field is created by flowing, electrically conducting fluid. As a planet cools, cold material sinks while hot material rises, a process called convection. If this flowing material conducts electricity, it generates a magnetic field.
Earth’s field comes from its liquid iron outer core, creating a pattern that makes compasses point north. But Voyager 2 found that Uranus and Neptune have messy, disorganized fields, suggesting their internal structure works differently.
--- MORE AT LINK ---
I’m here for the humor.
Popcorn at the ready. This is gonna be a good one.
Don’t carry your phone in your back pocket, and you won’t have magnetic around...
I won’t do it!!
For goodness’ sake I’m 56 years old now.
..sweating profusely...hands shaking...
Go on... you know you want to.
I’m 56 and make jokes about Uranus all the time! Keep metal away from Uranus and you don’t have worry about the magnetism.
No electrons on Uranus, only Pootons.
Thanks Red Badger.
· join · view topics · view or post blog · bookmark ·
· post new topic · subscribe ·Google news searches: exoplanet · exosolar · extrasolar ·
Yep, there ought to be some pretty good jokes about Neptune.
They changed the name from Uranus to end that stupid joke once and for all.
“What’d they change it to?”
“Urectum.”
Magnetic fields around Uranus? Sounds like something to discuss with your proctologist.
>> Magnetic fields around Uranus?
Suddenly, “Sit on it and rotate!” actually becomes a possibility instead of merely a rude idiom!
I joke about Neptune all the time. Such a funny name. I mean, what’s so funny about Uranus?
I can figure out Neptune but don’t have a clue about Uranus!
tried to warn my proctologist about magnetic fields butt he insisted that it was Neptune’s fork that was the real problem to avoid. it wasn’t a tuning fork that impaled me though. now I’m stuck in the key of see.
Lol!
I winder if Mercury was the same kind of planet where all that’s left is the core?
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.
