A new kind of ice: 'amorphous' solid, water 'frozen in time'

• Recently, scientists have fashioned a previously unknown form of ice – one that might exist on our solar system’s icy moons.

Medium-density amorphous ice

• The researchers employed a process called ball milling to vigorously shake ordinary ice together with steel balls in a container cooled to minus-328 degrees Fahrenheit (minus-200 degrees Celsius).
• This yielded what they called “medium-density amorphous ice,” or MDA, which looked like a fine white powder.

What is amorphous ice?

• Amorphous ice consists of water molecules arranged in a disordered state, with no large-scale regularity to their orientations or positions.
• This kind of ice is most often found in space.
• Scientists have identified 20 different forms of crystalline ice and three forms of amorphous ice – one low density (discovered in the 1930s), one high density (discovered in the 1980s), and the new one in between.

PRelims Take Away

• Amorphous ice
• Crystalline ice