'Dust devils' over Mamers Valles captured by the HRSC camera
Outflow channels at the mouth of Mamers Valles on Mars
The Mamers Valles form a distinctive region of wide, channel-like valleys and trenches on Mars. At the end of a roughly 1000-kilometre course through the Arabia Terra highlands, at the transition to the lowlands, they form a deeply fractured landscape. Water, as well as ice that pushed its way down the valleys, left behind channels up to 25 kilometres wide. These are flanked by remnants of the highlands that were spared from erosion, with their mesas (table mountains) hinting at a once-continuous plateau.
Topographic map of the Mamers Valles in the north of Arabia Terra
DLR's HRSC (High Resolution Stereo Camera) onboard Mars Express captures the Martian surface from multiple angles using nine sensors. From these, the DLR Institute of Space Research and the Planetary Science and Remote Sensing Group at the Freie Universität Berlin calculate digital terrain models. The colour scale in the top right of the image indicates elevation values. This reveals that water flowing with high energy from the Mamers Valles in the south (left in the image) has eroded channels roughly 1500 metres deep into the highlands at the transition to the northern lowlands. In doing so, the water left behind mesas (table mountains) on either side, which are remnants of the highlands.
True-colour bird's-eye view of the northern part of the Mamers Valles on Mars
The mouth region of Mamers Valles lies at the transition from the Martian highlands to the planet's northern lowlands. Mars researchers also refer to this zone as the dichotomy boundary. The source region of the Mamers Valles lie approximately 1000 kilometres further south. In the mouth region, remnants of the highlands that have been largely spared by erosion stand as mesas. The image section extends approximately 240 kilometres in a north-south direction (due to the HRSC scanner imaging technique, north is on the right-hand side of the image) and 90 kilometres in an east-west direction.
Topographical overview map of the Arabia Terra region of Mars, featuring the Mamers Valles
The trench-like channels of the Mamers Valles drainage system extend in a south-north direction over roughly 1000 kilometres, from the ancient highlands of Arabia Terra to the lower plains near Deuteronilus Mensae. In its middle sections, the valley is approximately 25 kilometres wide and up to 1.2 kilometres deep. The mouth region of the valley is known as 'fretted terrain': a fractured landscape featuring numerous deep and very wide, labyrinthine valleys, flat-topped mesas, steep cliffs and glacier-like deposits. The region formed approximately 3.8 billion years ago, when our neighbouring planet transitioned from a wetter, geologically more active world into a colder one.
Credit:
NASA/JPL (MOLA)/FU Berlin
Diverse landforms on Mars – the mouth region of Mamers Valles
Although the mouth region of Mamers Valles lies at 45 degrees north latitude, ice deposits are still present there today. These are protected from sublimation by a layer of dust and debris known as glacial ice deposits. Typical of the transition from the Martian highlands in the south (on the left of the image) to the northern lowlands are mesas (table mountains) that have been spared from erosion by water and ice. The image resolution of the HRSC images, at 20 metres per pixel, allows a whole series of small dust devils to be identified. Some of these dust devils pick up dust at high speed and carry it across the Martian surface. Small boxes mark their positions at the time the image was taken. Water flowing down from the highlands has carved out deep outflow channels (valleys) up to 25 kilometres wide into the landscape.
Image processing |
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The images were acquired by the HRSC (High Resolution Stereo Camera) on 7 October 2024 during Mars Express orbit 26,423. The ground resolution is approximately 20 metres per pixel, and the image is centred at approximately 45 degrees north and 17 degrees east. The colour image was created using data from the nadir channel, which is aligned perpendicular to the Martian surface, as well as the colour channels of the HRSC. The oblique view was generated from the digital terrain model and data from the nadir and colour channels of the HRSC. The anaglyph image, which provides a three-dimensional impression of the landscape when viewed with red-blue or red-green glasses, was derived from the nadir channel and one stereo channel. The colour-coded topographic view is based on a digital terrain model of the region, from which the topography of the landscape can be derived. |