Titan serves as an intriguing subject for in-depth investigations of organic chemistry under unusual conditions. This Saturnian moon is abundant in nonpolar hydrocarbons like ethane and methane, alongside hydrogen cyanide (HCN), a highly relevant small polar molecule in prebiotic chemistry. Recent studies show that these notably polar compounds can mix at low temperatures, creating structures that challenge traditional chemical theories.
Artistic rendering of Kraken Mare, Titan’s extensive ocean of liquid methane. Image credit: NASA’s John Glenn Research Center.
Hydrogen cyanide is commonly found in the astrochemical landscape and has been detected in numerous celestial bodies, including the interstellar medium, comets, planets, moons, and dwarf planets.
This molecule ranks as the second most prevalent product anticipated from Titan’s atmospheric chemistry.
Dr. Martin Rahm, a researcher from Chalmers University of Technology, stated: “These remarkable discoveries enhance our understanding of something vast—a moon comparable in size to Mercury.”
In laboratory experiments, Rahm and his team combined hydrogen cyanide with methane and ethane at temperatures as low as 90 K (around -180 degrees Celsius).
At this temperature, hydrogen cyanide forms crystals, while methane and ethane exist as liquids.
Using laser spectroscopy to analyze these mixtures at an atomic level, researchers found that while the molecules remained intact, changes were still occurring.
To uncover what was happening, they conducted extensive computer simulations to explore thousands of potential molecular arrangements in the solid phase.
Ultimately, they discovered that the hydrocarbons infiltrated the hydrogen cyanide crystal lattice, leading to the formation of a stable new structure termed a cocrystal.
“The identification of unexpected interactions between these substances may influence our understanding of Titan’s geology and unique features such as lakes, oceans, and sand dunes,” Dr. Rahm explained.
“Moreover, hydrogen cyanide could be crucial in the abiotic synthesis of some life-building blocks, like amino acids for proteins and nucleobases for genetic material.”
“Consequently, our research offers valuable insights into the pre-emergent chemistry of life and the potential for life to evolve in extreme environments.”
of result Published in July 2025. Proceedings of the National Academy of Sciences.
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Fernando Izquierdo Ruiz and others. 2025. Hydrogen cyanide and hydrocarbons mix on Titan. PNAS 122 (30): e2507522122; doi: 10.1073/pnas.2507522122
Source: www.sci.news
