A region of ice or other frozen matter surrounding a pole of a planet.
More example sentences
- The data will be invaluable in determining the thickness of the planetary crust and charting the seasonal variation in the carbon dioxide ice sheets that make up the Martian polar caps.
- As the temperature on Mars increases, carbon dioxide gas will be released from the regolith and the polar cap as it melts (the south polar cap is composed of frozen carbon dioxide and ice).
- Previously, surface water ice had been documented on the northern polar cap of Mars, but this is the first time exposed water ice has been documented on the southern polar cap of the solar system's fourth planet.
Definition of polar cap in:
- The US English dictionary