What does it look like?
What is it?
This month’s ice structure will take you out of this world, and into the layers of Ganymede. Ganymede is the largest moon in our solar system and is thought to have a deep ice crust. In fact the depth of this crust is so much that the weight of the ice above it thought to generate enough pressure to transform the ice below it, forming this structure Ice III. In fact, recent work, at Jet Propulsion Laboratory shows that the inside of Ganymede could be a bit of ‘club sandwich’ with a number of layers of different ices and liquid.
Ice III forms when you compress water at just below room temperature, 250K. Like the more extreme ice VI it also forms in tetragonal symmetry – meaning that any snowflakes it makes with be square. Ice III is a disordered forme of ice, that is the water molecules are constantly flipping between two orientations. With sufficient time ice III will order, that is the flipping of the molecules will stop, and it will alter its structure slightly as a result to become Ice IX.
Where did the structure come from?
The crystal structure of Ice III is #1011024 in the Crystallography Open Database.