In a new study conducted by a team of scientists with the participation of Alexander Goncharov from the Carnegie Institution for Science examined how the hydrogen behaves under conditions similar to those at the giant planet interiors by using lab-made simulation. According to the researchers’ work, published in the journal Science, hydrogen found in the interior of giant planets gets squeezed under such astronomical pressures that it turns from a gas into liquid metal.
Hydrogen is the most abundant chemical element in the Universe, being found as a gas in giant planets such as Jupiter and Saturn, as well as in Earth’s atmosphere, but also as a liquid metal in the interior of the planets.
The hydrogen transformation from a gas into a metal under extreme pressures “has been a longstanding focus of attention in physics and planetary science,” as said Peter Celliers from the Lawrence Livermore National Laboratory.
Hydrogen can reflect giant planet interiors when under enough pressure
The study, which also gathered researchers from the University of California Berkeley, George Washington University, the French Alternative Energies and Atomic Energy Commission, University of Rochester, and the University of Edinburgh, focused on the transformation of the hydrogen, from a gaseous compound to a liquid metal, analyzing deuterium, the heavier hydrogen isotope.
The researchers analyzed the property of deuterium to either absorb or reflect light, and they noticed that this heavier hydrogen isotope moved from absorbing lightwaves to reflecting them when under pressure by six million times higher than the normal atmospheric pressure and at temperatures of less than 1,700 degrees Celsius.
Accordingly, deuterium became opaque from translucid at pressure by 1.5 million times higher than the normal one, while it switched to liquid metal and gained reflectivity at about 200 gigapascals (nearly 2 million times more than the normal pressure).
“To build better models of potential exoplanetary architecture, this transition between gas and liquid metal hydrogen must be demonstrated and understood. That is why we focused on pinpointing the onset of reflectivity in compressed deuterium, moving us closer to a complete vision of this important process,” explained Alexander Goncharov.