Deep Inside Uranus and Neptune, Hydrogen Moves in Spiral Paths Unlike Anything Seen Before

Deep inside Uranus and Neptune, scientists have identified signs of an unusual state of matter unlike anything observed under normal conditions.

At the center of the study is carbon hydride, observed behaving in a way that blurs the boundary between solid and liquid, with direct implications for planetary physics and magnetic fields.

Published in Nature Communications, the research comes at a time when more than 6,000 exoplanets have been identified. This growing catalog has pushed scientists to better understand planetary interiors by combining observational data, laboratory experiments, and theoretical modeling.

A New Form Of “Hot Ice” Under Extreme Conditions

The work by Cong Liu and Ronald Cohen focuses on the so-called “hot ices” believed to exist inside Uranus and Neptune. These layers, composed of water, methane, and ammonia, sit between the outer hydrogen-helium envelope and the rocky core.

Pressures in these regions range from 500 to 3,000 gigapascals, with temperatures between 4,000 and 6,000 Kelvin. Under such conditions, familiar compounds adopt entirely different structures. The study shows that even simple chemical systems can reorganize into unexpected phases when pushed to these extremes.

To investigate this environment, the researchers used quantum simulations supported by machine learning, enabling a detailed look at atomic behavior deep inside planetary interiors.

A Spiral Pathway For Hydrogen Atoms

The simulations reveal that carbon hydride forms a rigid hexagonal lattice. Within this structure, hydrogen atoms move in a highly unusual way. As reported in Nature Communications, they follow helical, spiral-like paths, creating a quasi-one-dimensional superionic state.

This behavior differs from typical superionic materials, where atomic motion occurs in all directions. Here, movement is constrained along defined channels. Ronald Cohen noted that:

“This newly predicted carbon-hydrogen phase is particularly striking because the atomic motion is not fully three-dimensional. Instead, hydrogen moves preferentially along well-defined helical pathways embedded within an ordered carbon structure.”

Magnetism In Ice Giants

The way hydrogen moves through this structure directly affects how heat and electricity circulate inside the planet. These properties are closely tied to the formation and geometry of magnetic fields.

Uranus and Neptune display unusual magnetic fields that are both tilted and offset from their centers. The presence of this superionic phase may help clarify how energy and electrical conductivity are distributed internally. Cong Liu emphasized that:

“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.” 

Enjoyed this article? Subscribe to our free newsletter for engaging stories, exclusive content, and the latest news.