polar cap

noun

Geology. the icecap situated at either end of the earth's poles.
Astronomy. either of the two bright areas around the poles of the planet Mars, consisting of water ice and frozen carbon dioxide.

polar cap

The mass of ice that covers either of the Earth's polar regions year-round.
The mass of frozen carbon dioxide and water that covers either of Mars's polar regions.

First recorded in 1890–95

If you want to go far north, there’s polar caps that have water ice in them.

As they rocketed back to the Magellan, the whole polar cap, an area hundreds of miles around the Sun-tap station, split apart.

The receptionist smiled icily at Tom, and then the smile vanished like a Martian polar cap.

When either polar cap is melting it is bordered by a bluish area, which Lowell attributes to the water produced by the melting.

It is said that no such line is visible during the formation of the polar cap with the approach of winter.

As the Martian winter comes on in the northern34 hemisphere, for example, the polar cap extends its borders to the temperate zone.

April 23, 2024inveterate

[in-vet-er-it ]

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