Under pressure, hydrogen offers a reflection of giant planet interiors

August 16, 2018, Carnegie Institution for Science
Jovian cloudscape, courtesy of NASA's Juno spacecraft. Credit: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstädt/Seán Dora

Lab-based mimicry allowed an international team of physicists including Carnegie's Alexander Goncharov to probe hydrogen under the conditions found in the interiors of giant planets—where experts believe it gets squeezed until it becomes a liquid metal, capable of conducting electricity. Their work is published in Science.

Hydrogen is the most-abundant element in the universe and the simplest—comprised of only one proton and one electron in each atom. But that simplicity is deceptive, because there is still so much to learn about it, including its behavior under conditions not found on Earth.

For example, although on the surface of giant planets, like our Solar System's Jupiter and Saturn, is a gas, just like it is on our own planet, deep inside these giant planetary interiors, scientists believe it becomes a metallic liquid.

"This transformation has been a longstanding focus of attention in physics and planetary science," said lead author Peter Celliers of Lawrence Livermore National Laboratory.

The research team—which also included scientists from the French Alternative Energies and Atomic Energy Commission, University of Edinburgh, University of Rochester, University of California Berkeley, and George Washington University—focused on this gas-to-metallic-liquid transition in 's heavier isotope deuterium. (Isotopes are atoms of the same element that have the same number of protons but a different number of neutrons.)

They studied how deuterium's ability to absorb or reflect light changed under up to nearly six million times normal atmospheric pressure (600 gigapascals) and at temperatures less than 1,700 degrees Celsius (about 3,140 degrees Fahrenheit). Reflectivity can indicate that a material is metallic.

They found that under about 1.5 million times normal atmospheric pressure (150 gigapascals) the deuterium switched from transparent to opaque—absorbing the light instead of allowing it to pass through. But a transition to metal-like reflectivity started at nearly 2 million times normal atmospheric pressure (200 gigapascals).

"To build better models of potential exoplanetary architecture, this transition between gas and metallic liquid hydrogen must be demonstrated and understood," Goncharov explained. "Which is why we focused on pinpointing the onset of reflectivity in compressed deuterium, moving us closer to a complete vision of this important process."

Explore further: Probing giant planets' dark hydrogen

More information: "Insulator-metal transition in dense fluid deuterium" Science (2018). science.sciencemag.org/cgi/doi … 1126/science.aat0970

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7 comments

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Surveillance_Egg_Unit
3.7 / 5 (6) Aug 16, 2018
It is uncanny how the clouds of the planet Jupiter exhibit such similarities to the famous painting by Vincent Van Gogh, "The Starry Night". Quite remarkable, I would say, as well as beautiful.

Transitioning under extreme pressure from Hydrogen gas to a liquid-metal as a lab-experimented model is possible on planet Earth. The next step, if they wished to make the attempt, would be to compress the liquid-metal into a Plasma - which would require 1M celsius temperature, which is impossible to accomplish on Earth. And there are preliminary steps to take wrt Fission.
691Boat
5 / 5 (2) Aug 17, 2018
It is uncanny how the clouds of the planet Jupiter exhibit such similarities to the famous painting by Vincent Van Gogh, "The Starry Night". Quite remarkable, I would say, as well as beautiful.

Transitioning under extreme pressure from Hydrogen gas to a liquid-metal as a lab-experimented model is possible on planet Earth. The next step, if they wished to make the attempt, would be to compress the liquid-metal into a Plasma - which would require 1M celsius temperature, which is impossible to accomplish on Earth. And there are preliminary steps to take wrt Fission.


Gonna be doing lots of Hydrogen fission, are ya? That's pretty nifty.
jonesdave
2.7 / 5 (7) Aug 17, 2018
Gonna be doing lots of Hydrogen fission, are ya? That's pretty nifty.


Yep. Creating 2 x number 0.5 on the periodic table!
691Boat
5 / 5 (3) Aug 17, 2018
Gonna be doing lots of Hydrogen fission, are ya? That's pretty nifty.


Yep. Creating 2 x number 0.5 on the periodic table!

Since there are often several different daughter pairs, there may be a 0.4 and a 0.6 on the periodic table we don't know about too!
jonesdave
2.6 / 5 (7) Aug 17, 2018
Gonna be doing lots of Hydrogen fission, are ya? That's pretty nifty.


Yep. Creating 2 x number 0.5 on the periodic table!

Since there are often several different daughter pairs, there may be a 0.4 and a 0.6 on the periodic table we don't know about too!


Or maybe it just fissions into its constituent quarks. Not sure how much energy that would release. Quark bomb, anybody?
691Boat
5 / 5 (2) Aug 17, 2018
@Jones: fat fingered and gave you a 4 instead of a 5. I like the idea of a quark bomb!
katesisco
1 / 5 (1) Aug 18, 2018
I was thinking in a magnetized compressed gas cloud the deuterium could be reflective which would explain our 'Nibiru" images. Also wondered if a magnetically compressed gas cloud in a plasma exchange would draw upon the O2 leaving the atmosphere with less O2 content. Hence a global water vapor fall.

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