Ice in space behaves differently? Scientists discover hidden crystal structure in cosmic snow

Scientists have found that water ice in space isn't completely disordered as once believed. New research shows that up to 25% of so-called amorphous ice actually contains tiny crystals, changing how we understand space and life’s origins.

Water ice is found all across the universe on frozen moons, distant planets and even in interstellar clouds. But until now, scientists believed that ice in space was completely shapeless and lacked the structured patterns seen in Earth’s snowflakes.

On Earth, ice forms in warmer conditions where water molecules have enough energy to arrange themselves into a neat, crystalline structure, like snowflakes. But in the extreme cold of space, temperatures drop so low that scientists thought water would freeze into an amorphous form, meaning it had no pattern or order at the molecular level.

A surprising discovery from deep-freeze simulations

Researchers at University College London (UCL) and the University of Cambridge have now found something surprising that even ice in deep space isn’t completely random. Using advanced computer simulations and X-ray diffraction experiments, they discovered that up to 25% of the ice could actually be crystalline, even if it looks disordered on the surface.

This is a major change from what scientists previously believed.

How the scientists tested the theory

The research team created two kinds of computer simulations:

• One simulation froze water at very cold temperatures (-120°C or -184°F) at different rates.
• The second simulation started with well-structured ice and then randomly mixed up the molecules.

The results were unexpected. The first simulation created ice that was around 20% crystalline, with small crystals just 3 nanometers wide. The second showed an even higher percentage of crystals, up to 25%.

To confirm the results, scientists used X-ray beams to study real samples of so-called amorphous ice. They looked at how the X-rays bounced off the molecules, and what they saw matched the simulated results.

Space ice may remember its past

One important finding was that the structure of the ice changed depending on how it was formed. If amorphous ice had no crystal memory, its structure would not vary. But it did, proving that some crystals remained inside, hidden in the ice.

This suggests that space ice is not fully forgetful. It carries some structural “memory” of how it formed, which could be important for understanding how planets and stars grow from cold clouds in space.

Why this matters for space travel and the origin of life

Knowing the true nature of space ice has many practical and scientific uses:

Radiation shielding: Crystalline ice might better protect spacecraft from harmful cosmic rays.

Rocket fuel source: Ice can be split into hydrogen and oxygen, which are key rocket fuels.

Organic chemistry: Some scientists believe that the ingredients for life arrived on Earth through icy dust grains from space. These findings suggest that crystalline areas may hold less organic material, but the amorphous parts could still carry life’s building blocks.

As lead researcher Michael B. Davis said, "Ice plays a role in how planets form, how galaxies evolve, and how matter moves around the universe."

The future of space ice research

This discovery opens up new questions for scientists. What other hidden properties might space ice have? Could it behave differently on moons like Europa or Enceladus? And how might it have helped bring life’s ingredients to Earth?

One thing is clear that space ice is much more complex and structured than we once believed.