{ "title": "Dunes on the Rim of the Hellas Impact Basin", "authors": "HiRISE", "metadata": { "thumbnailURL": "https://static.uahirise.org/anews/2020-12-08/ESP_034101_1385.jpg", "excerpt": "Sand dunes like these seen in this image have been observed to creep slowly across the surface of Mars through the action of the wind." }, "version": "1.5", "identifier": "ESP_034101_1385", "language": "en", "layout": { "columns": 10, "width": 1024, "margin": 85, "gutter": 20 }, "documentStyle": { "backgroundColor": "#faf7f2" }, "components": [ { "role": "heading1", "layout": "heading1Layout", "text": "HiPOD: 8 December 2020" }, { "role": "divider", "layout": "bigDividerLayout", "stroke": { "width": 3, "color": "#8c2028" } }, { "role": "title", "layout": "halfMarginBelowLayout", "text": "Dunes on the Rim of the Hellas Impact Basin" }, { "role": "photo", "layout": "fullBleedLayout", "caption": "An enhanced color cutout showing one of the barchan dunes. Less than 1 km across. (NASA/JPL/UArizona)", "URL": "https://static.uahirise.org/anews/2020-12-08/ESP_034101_1385.jpg" }, { "role": "body", "format": "html", "layout": "hipodMarginLayout", "text": "


Sand dunes like these seen in this image have been observed to creep slowly across the surface of Mars through the action of the wind. These are a particular type of dune called a “barchan”, which forms when the wind blows in one direction (here, east to west) for long periods of time. Barchan dunes are common on Mars and in the desert regions of the Earth.

These barchan dunes are located on the western rim of the Hellas impact basin, in the Southern Hemisphere of Mars. Careful comparison of repeat images such as these can reveal the speed and manner by which dunes move across the Martian surface. This information can be used to study the current atmosphere of Mars, the age and mobility of sand deposits on the planet’s surface, and the hazards that sand dunes may pose to landed vehicles such as rovers.

" }, { "role": "photo", "layout": "fullBleedLayout", "caption": "This area is covered by extensive deposits of layered rocks that were initially deposited as loose sediments and over time formed these rock layers. Portions of these layered rocks were subsequently eroded away and the remaining layers now form numerous flat-topped hills called “mesas”. The barchan dunes are forming in the lee (or downwind) of the mesas. Less than 5 km across. (NASA/JPL/UArizona)", "URL": "https://static.uahirise.org/anews/2020-12-08/ESP_034101_1385-2.jpg" }, { "role": "body", "format": "html", "layout": "hipodMarginLayout", "text": "

ID: ESP_034101_1385
date: 4 November 2013
altitude: 252 km (157 mi)

NASA/JPL/UArizona

" }, { "role": "caption", "format": "html", "layout": "halfMarginBothLayout", "text": "Enhanced color image is less than 1 km across; black and white image is less than 5 km. For full images with scalebars, see the above ID link to our website.

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