Claim: Antarctica is in a polar region.

Ice is water frozen into a solid state . Depending on the presence of impurities such as particles of soil or bubbles of air , it can appear transparent or a more or less opaque bluish-white color .   In the Solar System , ice is abundant and occurs naturally from as close to the Sun as Mercury to as far away as the Oort cloud objects . Beyond the Solar System , it occurs as interstellar ice . It is abundant on Earth 's surfaceparticularly in the polar regions and above the snow lineand , as a common form of precipitation and deposition , plays a key role in Earth 's water cycle and climate . It falls as snowflakes and hail or occurs as frost , icicles or ice spikes .   Ice molecules can exhibit seventeen or more different phases -LRB- packing geometries -RRB- that depend on temperature and pressure . When water is cooled rapidly -LRB- quenching -RRB- , up to three different types of amorphous ice can form depending on the history of its pressure and temperature . When cooled slowly correlated proton tunneling occurs below 20 K giving rise to macroscopic quantum phenomena . Virtually all the ice on Earth 's surface and in its atmosphere is of a hexagonal crystalline structure denoted as ice I -LRB- spoken as `` ice one h '' -RRB- with minute traces of cubic ice denoted as ice I . The most common phase transition to ice I occurs when liquid water is cooled below at standard atmospheric pressure . It may also be deposited directly by water vapor , as happens in the formation of frost . The transition from ice to water is melting and from ice directly to water vapor is sublimation .   Ice is used in a variety of ways , including cooling , winter sports and ice sculpture .