It may come as a surprise to most that there’s not just one type of ice. In fact, there are 17—varying substantially in structure and weight—and an 18th “in development.” Only two types appear naturally on Earth, the common hexagonal version and upper-atmosphere cubic ice, but scientists have been able to produce “a type of porous, lightweight ‘aeroice'” according to New Scientist. Pressure causes variations as water freezes in a more dense fashion under intense conditions. But Masakazu Matsumoto, at Okayama University in Japan, recently found two lightweight versions, one of which is gel-like and at an ultralow-density. And they did so by playing “molecular Jenga” to make it happen.