Friday 21 March 2025
Researchers have made a significant breakthrough in understanding how carbon dioxide is produced on icy bodies like Europa, Ganymede, and Enceladus. By studying the sputtering of organic molecules in water ice at low temperatures, scientists have uncovered a previously unknown pathway for CO2 formation.
The process begins with the presence of functionalized hydrocarbons – molecules containing carbon and hydrogen atoms attached to other functional groups like carboxylic acids or alcohols. These molecules are commonly found on icy bodies and can be upwelled from the subsurface oceans onto the surface through geological processes.
When these organic molecules are exposed to high-energy electrons, such as those produced by solar flares or radiation from nearby stars, they undergo a process called electron-induced sputtering. This involves the ejection of atoms and molecules from the surface of the ice, which can lead to the formation of new compounds.
In this study, researchers focused on the sputtering of hexanoic acid, a common organic molecule found on icy bodies, in water ice at temperatures ranging from 80K to 120K. They discovered that the presence of carboxylic acid functional groups in these molecules significantly enhances the production of CO2.
The results show that the majority of CO2 produced during sputtering is not generated through radiolysis – a process where high-energy radiation breaks down water ice and produces CO2 as a byproduct. Instead, the CO2 is formed through the direct fragmentation of organic molecules.
This new pathway for CO2 formation has significant implications for our understanding of the origins of carbon dioxide on icy bodies. It suggests that organics upwelled from subsurface oceans could be contributing to the presence of CO2 on the surface and in the exosphere, rather than solely being generated through radiolysis.
The study’s findings also have important implications for future missions to explore these icy bodies. By understanding how CO2 is produced on these worlds, scientists can better design instruments and experiments to detect and analyze this critical component of their atmospheres.
In addition to its significance for astrobiology, the research has broader implications for our understanding of the chemistry of water ice at low temperatures. The study’s results demonstrate that even at very low temperatures, complex chemical reactions can occur, leading to the formation of new compounds like CO2.
The discovery of this new pathway for CO2 formation is a testament to the power of interdisciplinary research and collaboration between scientists from different fields.
Cite this article: “Unveiling a New Pathway for Carbon Dioxide Formation on Icy Bodies”, The Science Archive, 2025.
Carbon Dioxide, Icy Bodies, Europa, Ganymede, Enceladus, Organic Molecules, Water Ice, Low Temperatures, Electron-Induced Sputtering, Astrobiology
