NASA astronaut shares image of impossible-looking ‘hopper’ crystal growing on the space station. What is happening?
Astronauts have grown a common crystal in space – but this extraterrestrial version is exhibiting a very unusual behavior. under a microscope, crystal It looks more like a miniature sculpture from the future than something that would have formed naturally. The pyramid-like assembly folds in on itself in stair-stepped layers that seem almost too organized to be real. But according to scientists, the striking shape occurs when gravity stops striking.
Microgravity is not exactly zero gravity; Astronauts experience a gravitational pull about a million times weaker than on Earth’s surface, Anne Wilsona professor of chemistry and biochemistry at Butler University told Live Science. The reduction in gravitational pull has a profound effect effect on human bodyAnd, as the new image shows, it also completely changes the behavior of liquids and crystals.
“[Other] The forces start out to be much more pronounced than gravitational forces,” Wilson said, pointing to molecular attraction and polarity as two effects that suddenly become dominant as gravity fades into the background.
those conditions enable potassium chloride – a common salt used as a substitute for sodium in foods and sports drinks – known to crystallize in ways that are almost impossible to reproduce in a terrestrial laboratory.
On Earth, growing crystals eventually become so heavy that they break loose, break or settle to the bottom of their container. But in microgravity, they keep moving outward from wherever they started.
Potassium chloride naturally forms cube-shaped crystals, Wilson said. In microgravity, those crystals grow primarily from their edges and corners rather than their faces, leaving the center hollow and forming the striking pyramid-like structures seen in the image.
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In microgravity, crystals experience “hopper growth”, where the outer edges and corners grow at a faster rate than flat surfaces, creating a step-like appearance. This timelapse records their growth inside a thin water film. Look closely, and you’ll see patterns emerge! pic.twitter.com/iSlqJvke1G6 June 2026
scientists call it patterns hopper riseAnd this isn’t unique to potassium chloride (common table salt is made the same way). As new vertices emerge during growth, the crystal can completely change direction, producing the beautiful scrolling pattern seen in the new image.
While crystals are stunning to look at, the science behind them may prove to be just as valuable. Materials grown without the interference of gravity often form with fewer defects, giving researchers a rare look at what an “ideal” structure actually looks like. This insight could help refine manufacturing processes for semiconductors and other advanced materials on Earth.
For Wilson, such images serve another purpose: inspiring curiosity.
“I like watching videos of how things behave in space,” he said. “Who would think that something as simple as potassium chloride could still be super cool?”
ISS astronauts spend a large part of their time conducting science experiments that would be nearly impossible on Earth. Recently, astronauts used the space station’s newly upgraded Cold Atom Laboratory Create and study an elusive fifth state of matter Called Bose-Einstein condensate. And last year, researchers demonstrated how algae spores survived outside the ISS exposed to space for nine months kept growing After coming back to Earth.
