SLAC Finds Diamond Rain Starts Below 2 Million Atmospheres, Reshaping Uranus and Neptune Magnetic-Field Models
Updated
Updated · spacedaily.com · Jun 9
SLAC Finds Diamond Rain Starts Below 2 Million Atmospheres, Reshaping Uranus and Neptune Magnetic-Field Models
1 articles · Updated · spacedaily.com · Jun 9
Summary
January 2024 results showed diamond rain in ice-giant interiors begins at lower pressures and temperatures than earlier SLAC experiments had indicated, implying the process starts at shallower depths than the roughly 10,000 kilometers once modeled.
Two laser-driven shock waves compressed plastic samples to Neptune-like conditions for femtoseconds, while X-ray diffraction captured carbon separating from hydrogen and crystallizing into nanodiamonds in real time.
That broader diamond-forming zone could help explain why Uranus and Neptune have magnetic fields that are unusually offset from their rotational axes, by disrupting convection inside their fluid interiors.
Earlier SLAC work in 2017 first directly observed the process, and follow-up experiments in 2020 and 2022 confirmed it still occurs in oxygen-bearing mixtures closer to the planets' methane-water-ammonia chemistry.
The findings extend beyond the solar system because many exoplanets are Neptune-like; SLAC's next experiments aim to reach 5 million to 10 million atmospheres to probe deeper planetary chemistry.
If Neptune holds more diamonds than Earth, what other common materials become cosmic treasures under the pressures of alien worlds?
Does a bizarre superionic 'hybrid' matter, not diamond rain, truly explain the mysteries hidden deep inside ice giants?
From Diamond Rain to Magnetic Fields: The Science Transforming Our View of Icy Giants and Exoplanets
Overview
Recent international collaborations, involving leading research centers like European XFEL, DESY, and HZDR, have led to major breakthroughs in understanding diamond rain formation inside icy giant planets such as Neptune and Uranus. This work, highlighted in a 2024 Nature Astronomy paper by a large team including Mungo Frost and Alexander F. Goncharov, has provided crucial insights into how diamonds form deep within these planets. The new knowledge is helping scientists unravel the complex interior dynamics of Neptune and Uranus, and is also improving our understanding of the Solar System’s structure and the evolution of icy worlds.