Contrary to popular belief, the ice that populates the Universe isn't completely disordered. Researchers have just detected the presence of nanocrystals within it, challenging decades of scientific certainties.
This discovery sheds new light on the composition of so-called "amorphous" ice, which is predominant in comets, icy moons, and interstellar clouds. Through innovative simulations and experiments, a British team has demonstrated that this ice actually hides an unsuspected level of organization.
M. Davies/University College London A more complex structure than expected
Numerical simulations reproduced water freezing at -120°C (-184°F), revealing that 20% of the ice adopted a crystalline structure. These nanocrystals, measuring just three nanometers across, better explain existing experimental data than the purely amorphous model.
The researchers then created different forms of ice in the laboratory. When warming these samples, they observed that each retained a "memory" of its initial formation. This structural persistence betrays the presence of an underlying organization.
These results contradict the hypothesis that space cold would prevent any crystallization. For physicist Michael Davies, this breakthrough finally allows visualization of the atomic structure of the most widespread ice in the cosmos.
Cosmological and technological implications
The discovery impacts several fields, particularly panspermia theory. While nanocrystals reduce available space for trapping organic molecules, amorphous areas remain capable of transporting life's building blocks through space.
Earth applications are equally promising. As chemist Christoph Salzmann points out, amorphous materials used in fiber optics could gain performance if their potential microcrystals were eliminated.
Finally, this research opens new avenues for exploiting space ice. Its particular structure could make it an ideal material for protecting spacecraft from radiation or storing space fuels.
Article author: Cédric DEPOND