Researchers from Northeastern University are among the many scientists helping NASA use the weightlessness of space to design stronger materials here on Earth.

Structural alloys might not sound familiar, but they are an integral part of everyday materials, such as , car bodies, engine blocks, or . These materials are produced through solidification—a process similar to the making of ice cubes. “Solidification happens all around us, either naturally, as during the crystallization of familiar snow-flakes in the atmosphere, or in technological processes used to fabricate a host of materials, from the large  used for solar panels to the making of almost any man-made object or structure that needs to withstand large forces, like a turbine blade,” said Northeastern University Prof. Alain Karma, who was a collaborator in this study.

The transition of a structural alloy from liquid to solid is morphologically unstable, meaning that the interface between solid and liquid evolves from a planar morphology to a non-planar cellular structure during solidification—essentially, the same instability is responsible for the branched star shape of snow flakes.