{ "title": "HiPOD", "metadata": { "thumbnailURL": "bundle://header.jpg", "excerpt": "It’s spring in the Northern Hemisphere of Mars, and this area was recently completely covered by the seasonal frost cap." }, "version": "1.5", "identifier": "ESP_060685_2480", "language": "en", "layout": { "columns": 10, "width": 1024, "margin": 85, "gutter": 20 }, "documentStyle": { "backgroundColor": "#faf7f2" }, "components": [ { "role": "heading1", "layout": "heading1Layout", "text": "HiPOD: WEDNESDAY, 20 NOVEMBER 2019" }, { "role": "divider", "layout": "bigDividerLayout", "stroke": { "width": 3, "color": "#8c2028" } }, { "role": "title", "layout": "halfMarginBelowLayout", "text": "Polygonal Patterns Highlighted by Frost" }, { "role": "video", "layout": "fullBleedLayout", "URL": "https://www.uahirise.org/media/clips/ESP_060685_2480_1080.mp4", "stillURL": "bundle://video-still.jpg", "accessibilityCaption": "A narrated and close-captioned clip of this observation. Narration by Tre Gibbs." }, { "role": "body", "format": "html", "layout": "hipodMarginLayout", "text": "
It’s spring in the Northern Hemisphere of Mars, and this area was recently completely covered by the seasonal frost cap. Here, we see polygonal patterns that are highlighted by carbon dioxide frost that has not entirely sublimed away.
These organized patterns are likely caused by differences in the soil (regolith) characteristics such as grain size, density, even grain-shape and orientation in the underlying landforms and geologic materials. Variations in these characteristics strongly influence the strength of the ice-rich permafrost. This gives a preferred orientation to the stress field that produces the polygonal patterns.
ID: ESP_060685_2480
date: 8 July 2019
altitude: 314 km
NASA/JPL/University of Arizona