Hidden Nanocrystals in Cosmic Ice Rewrite Astrophysics and Origin-of-Life Theories

Location: London, U.K.

In a landmark study published today in Physical Review B, researchers from University College London (UCL) and the University of Cambridge reveal that the most common form of ice in the cosmos—previously believed to be purely amorphous—is actually interspersed with tiny crystalline regions roughly three nanometers wide, slightly larger than the diameter of a single DNA strand. Through a combination of advanced computer simulations and meticulously controlled laboratory experiments, the team demonstrated that models of space ice containing up to 20% crystalline material best match existing X-ray diffraction data.

The discovery overturns decades-old assumptions about “space ice,” which forms on comets, icy moons, and in interstellar dust clouds at temperatures so low that water molecules were thought incapable of organizing into crystals. Simulations of water freezing at −120 °C showed that when ice contains microscopic crystals embedded within a disordered matrix, it reproduces experimental observations far more accurately than a fully amorphous model. Laboratory samples of low-density amorphous ice—produced by vapor deposition onto cold surfaces and by warming compressed high-density ice—retained structural “memory” of their formation pathways, confirming the presence of hidden crystalline order.

This breakthrough has profound implications across multiple fields:

• Astrophysics & Planet Formation: Understanding the true atomic structure of cosmic ice refines models of dust-grain aggregation and planetesimal evolution in protoplanetary disks.

• Origin-of-Life Research: The presence of nanocrystals reduces the available amorphous volume for trapping complex organic molecules, slightly challenging—but not disproving—theories of cometary delivery of life’s building blocks to early Earth.

• Materials Science & Technology: Revealing hidden crystals in amorphous solids may inform the design and performance optimization of disordered materials used in fiber optics, radiation shielding, and high-performance aerospace components.

“Our results show that ice in the Universe is a far more intricate material than we thought. Tiny crystals could influence processes from how planets form to how we design durable materials on Earth,” said lead author Dr. Michael B. Davies of UCL’s Department of Physics.

Illustration of nanocrystals within cosmic ice in space