It would seem that science knows everything about water, which covers about 71% of the surface of our planet. But this is far from the case. As a result of recent research, scientists at the University of Lincoln, Nebraska, led by Professor Xiao Cheng Zeng, have discovered a new type of super-light ice crystals. Thus, the total number of different types of ice has reached 18.
Most of them are lighter than water, as evidenced by the "buoyancy" of ice. Scientists have found that under certain conditions, water molecules can line up in an unusual way. Together with colleagues at Deline University of Technology, they discovered a type of ice where the molecules form an interconnected cell-like structure called "clarate." A prerequisite for this is extreme pressure causing the molecules to expand.
Previously, this team of researchers discovered another form of 2D ice, which, on the contrary, shrinks rather than expands during freezing under certain conditions. However, it is worth mentioning that new unusual forms of ice are just speculations of scientists. They have yet to be synthesized, because there are no necessary conditions in the natural environment of the Earth.
Nevertheless, these studies are of great value, since they will help scientists understand the state of water on other planets.