On Saturn’s moon Titan, scientists have observed the formation of strange crystals from substances that, according to known chemistry, should not combine.
The result, obtained by researchers from NASA and Chalmers University of Technology in Sweden, calls into question a basic rule of chemistry and shows that, under extreme conditions, matter can behave unexpectedly. The team found that molecules previously considered incompatible, such as hydrogen cyanide – a polar substance, and methane and ethane, non-polar molecules, can form stable solid structures in the intense cold on Titan, where temperatures drop to minus 180°C.
On Titan, chemistry plays by different rules
Normally, these types of molecules repel each other, according to the chemical principle “like dissolves like”: polar substances, such as water, only mix with each other, and non-polar substances, such as oil, do the same without combining with each other. On Titan, however, the rules seem to be different – there, methane and ethane manage to penetrate the crystal structure of hydrogen cyanide, forming a type of hybrid crystals, unknown until now.
“These are very interesting discoveries because they can help us understand something on a large scale – a moon as big as the planet Mercury,” said Swedish chemist Martin Rahm, one of the authors of the study, quoted by Science Alert.
