Space Ice Reveals Unexpected Crystalline Structure

Contrary to long-held beliefs, “space ice” isn’t fully amorphous. Research reveals it contains tiny crystals, impacting our understanding of the universe and potentially, the origins of life.

Crystals in Space Ice

Scientists at UCL and the University of Cambridge have discovered that low-density amorphous ice, the most common type of ice in space, contains tiny crystals about three nanometers wide. These findings challenge the assumption that space ice is entirely disordered, like liquid water.

The research team, led by **Dr. Michael B. Davies**, found that computer simulations closely matched experimental measurements when the ice was modeled with embedded nanocrystals.

According to **Dr. Davies**: “We now have a good idea of what the most common form of ice in the Universe looks like at an atomic level.” He added, “This is important as ice is involved in many cosmological processes, for instance in how planets form, how galaxies evolve, and how matter moves around the Universe.”

Implications for the Panspermia Theory

The discovery has implications for the Panspermia theory, which suggests that the building blocks of life were transported to Earth via icy comets. If space ice contains crystals, it might be a less suitable medium for carrying these molecules. However, **Dr. Davies** notes that amorphous regions within the ice could still trap and store life’s building blocks.

A study published in *Nature Astronomy* in 2023 found that complex organic molecules, including amino acids, can indeed form within interstellar ice under space-like conditions (Nature Astronomy 2023).

Ice’s Structure Holds Clues

**Professor Christoph Salzmann**, of UCL Chemistry, explained: “Ice on Earth is a cosmological curiosity due to our warm temperatures. You can see its ordered nature in the symmetry of a snowflake.”

He added: “Ice in the rest of the Universe has long been considered a snapshot of liquid water – that is, a disordered arrangement fixed in place. Our findings show this is not entirely true.”

Research Methodology

The researchers used computer models to freeze water molecules at different rates, creating varying proportions of crystalline and amorphous ice. They found that ice with up to 20% crystallinity closely matched the structure of low-density amorphous ice.

Experimental work involved re-crystallizing real samples of amorphous ice. The resulting crystal structure varied based on how the ice had originally formed, suggesting that amorphous ice retains a “memory” of its origin.

Future Directions

The findings raise questions about the nature of amorphous ices, including variations in crystal size and the possibility of truly amorphous ice.

**Professor Angelos Michaelides**, from the University of Cambridge, stated: “Water is the foundation of life but we still do not fully understand it. Amorphous ices may hold the key to explaining some of water’s many anomalies.”

According to **Dr. Davies**: “Ice is potentially a high-performance material in space. It could shield spacecraft from radiation or provide fuel in the form of hydrogen and oxygen. So we need to know about its various forms and properties.”