Tag Archives: CO2 frost

HiRISE: Defrosting dunes within Chasma Boreale

This image shows a dune field in Chasma Boreale, which is a large trough that cuts into the North Polar ice cap. Some of the dunes in this image are quite long and sinuous with a slight bulge at one … Continue reading

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THEMIS: Frosty dunes in Siton Undae

THEMIS Image of the Day, September 18, 2017. Siton Undae is a large dune field located in the northern plains near Escorial Crater. Siton Undae is west of the crater and is one of three dune fields near the crater. … Continue reading

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HiRISE: A world of snowy dunes

It is spring in the Northern hemisphere when we took this image. Over the winter, snow and ice have inexorably covered the dunes. Unlike on Earth, this snow and ice is carbon dioxide, better known to us as dry ice. … Continue reading

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HiRISE: Frosted valleys

Frosted valleys. Beautiful Mars series.

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THEMIS: Frost and south polar trough layers

THEMIS Image of the Day, June 26, 2017. Do you see what I see? Don’t be afraid, but it looks like a ghost! (THEMIS Art #133) More THEMIS Images of the Day by geological topic.

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THEMIS: South polar ice features

THEMIS Image of the Day, June 9, 2017. Today’s VIS image shows more of the south polar cap at the end of southern summer. More THEMIS Images of the Day by geological topic.

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THEMIS: South polar textures as local summer ends

THEMIS Image of the Day, June 8, 2017. This VIS image of the south pole was taken at the end of summer. Frost will soon start to form as the season transitions into fall. Fall in the southern hemisphere means … Continue reading

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HiRISE: A winter’s view of a gullied crater

This is the location with the most impressive known gully activity in the Northern hemisphere. Gullies are active in the winter due to carbon dioxide frost, but northern winters are shorter and warmer than southern winters, so there is less … Continue reading

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HiRISE: Gullies in winter shadow

This is an odd-looking image. It shows gullies during the winter while entirely in the shadow of the crater wall. Illumination comes only from the winter skylight. We acquire such images because gullies on Mars actively form in the winter … Continue reading

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HiRISE: How gas carves channels

A layer of dry ice covers the South Polar layered deposits every winter. In the spring, gas created from heating of the dry ice escapes through ruptures in the overlying seasonal ice, entraining material from the ground below. The gas … Continue reading

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