New Insights into the Interiors of Uranus and Neptune: The Discovery of a Superionic State

Recent computational simulations by researchers Cong Liu and Ronald Cohen from the Carnegie Institution for Science suggest that the interiors of ice giant planets, specifically Uranus and Neptune, may host a previously unknown state of matter known as a quasi-one-dimensional superionic state of carbon hydride (CH). This discovery, published in *Nature Communications*, indicates that under the extreme pressures and temperatures found deep within these planets, carbon hydride can form an ordered hexagonal structure where hydrogen atoms move along spiral pathways.

New Form of Matter May Lurk Deep Inside Uranus and NeptuneThe depths of Neptune and Uranus may be “superionic”The depths of Neptune and Uranus may be “superionic”

Measurements of Uranus and Neptune's densities imply that their interiors contain intermediate layers of unconventional "hot ices," situated beneath hydrogen and helium atmospheres and above rocky cores. These layers are believed to consist of water (H2O), methane (CH4), and ammonia (NH4). The extreme conditions within these layers lead to the emergence of exotic phases of matter, prompting scientists to explore the physical processes occurring in these high-pressure environments.

The depths of Neptune and Uranus may be “superionic”The depths of Neptune and Uranus may be “superionic”New Form of Matter May Lurk Deep Inside Uranus and Neptune

Liu and Cohen utilized high-performance computing and machine-learning techniques to conduct quantum physics simulations of carbon hydride under pressures ranging from approximately 5 million to 30 million times atmospheric pressure (500 to 3,000 gigapascals) and temperatures between 4,000 to 6,000 Kelvin. Their findings revealed that hydrogen atoms in this superionic state do not move in a fully three-dimensional manner; instead, they follow well-defined helical pathways within a structured carbon framework.

New Form of Matter May Lurk Deep Inside Uranus and Neptune

The directional movement of hydrogen atoms in this superionic state has significant implications for understanding heat and electricity distribution within planetary interiors. This behavior could affect energy redistribution, electrical conductivity, and the interpretation of magnetic field generation in ice giants. Furthermore, the research expands the understanding of how simple compounds behave under extreme conditions, indicating that even basic systems can organize into complex phases.

The depths of Neptune and Uranus may be “superionic”The depths of Neptune and Uranus may be “superionic”New Form of Matter May Lurk Deep Inside Uranus and Neptune

While the findings provide valuable insights into planetary interiors, some experts emphasize the need for further experimental validation of these simulations. The ability to identify emergent phenomena in condensed matter could also have ramifications for materials science and engineering, potentially influencing the development of new materials with unique properties.

The depths of Neptune and Uranus may be “superionic”

• “This newly predicted carbon-hydrogen phase is particularly striking because the atomic motion is not fully three-dimensional,” — Dr. Ronald Cohen, Carnegie Institution for Science

New Form of Matter May Lurk Deep Inside Uranus and Neptune

• “Carbon and hydrogen are among the most abundant elements in planetary materials, yet their combined behavior at giant-planet conditions remains far from fully understood,” — Dr. Cong Liu, Carnegie Institution for Science

The depths of Neptune and Uranus may be “superionic”

The research conducted by Liu and Cohen marks a significant advancement in the understanding of planetary dynamics and the potential for habitability in distant celestial bodies, paving the way for future explorations of the outer Solar System.

The depths of Neptune and Uranus may be “superionic”