This colour image was created using data from the nadir channel, the field of view of which is which is directed vertically down onto the Martian surface, and the High Resolution Stereo Camera (HRSC) colour channels; north is to the right in the image. Even though the ochre-coloured shadows associated with Mars dominate the landscape, the image data from the four HRSC colour channels can be processed to enable the material and textural differences on the surface of Mars to be accentuated to a degree. This can be seen, for example, in the low plains to the west of the region (upper left in the image), in the valley surrounded by hills in the right half of the image and in the neighbouring valleys. These colour differences may be related to variations in the geological composition of the surface of Mars, or they might be caused by differing material properties such as disparate particle sizes or dissimilar degrees of compaction.

Credit: ESA/DLR/FU Berlin (G. Neukum).

The nadir channel, the field of view of which is which is directed vertically down onto the Martian surface, provides the highest image resolution in the High Resolution Stereo Camera (HRSC) camera system. During orbit 9465, the ESA Mars Express spacecraft was about 400 kilometres above the surface, resulting in an image resolution of 16 metres per pixel. To improve the depiction, the resolution in the images shown here has been slightly reduced; north is to the right. In the framed areas, conspicuous phenomena characteristic of the region are visible: elongated, parallel flow patterns in valley-shaped depressions (box 1), hills around which plastic material has flowed (box 2), and partially filled impact craters in which the flow structures are aligned parallel to the crater rim (box 3).

Credit: ESA/DLR/FU Berlin (G. Neukum).

Realistic perspective views of the Martian surface can be generated from data acquired by the stereo and colour channels of the High Resolution Stereo Camera (HRSC) on ESA's Mars Express spacecraft, which are oriented at an angle with respect to the planet’s surface. A valley-shaped depression can be seen in the centre of the image, which has been partly filled with material that has presumably been transported there from the hills in the higher Phlegra Montes. Flow patterns can be seen on the surface of the valley floor, indicating that this material had viscoplastic flow properties. The flow patterns, which are aligned in parallel, bear a strong similarity to the surfaces of 'rock glaciers' on Earth. Such bodies of ice are interspersed with boulders and rocky debris and occur on Earth primarily in regions of permafrost on high mountain ranges or at polar latitudes.

Credit: ESA/DLR/FU Berlin (G. Neukum).

Realistic perspective views of the Martian surface can be generated from data acquired by the stereo and colour channels of the High Resolution Stereo Camera (HRSC) on ESA’s Mars Express spacecraft, which are oriented at an angle with respect to the planet's surface. This image shows an impact crater in the foreground, which has been filled with material with plastic properties – presumably via the gap in the crater rim on the left hand side. This can be seen in the flow patterns that have formed in the interior of the crater, in part parallel to the crater rim. These can also be seen on the surface of the area surrounding the crater. Flow patterns can also be seen in the valley-shaped depression in the centre of the image. These might have arisen from 'rock glaciers' – bodies of ice interspersed with boulders and rocky debris that also occur on Earth, primarily in regions of permafrost on high mountain ranges or at polar latitudes.

Credit: ESA/DLR/FU Berlin (G. Neukum).

Realistic perspective views of the Martian surface can be generated from data acquired by the stereo and colour channels of the High Resolution Stereo Camera (HRSC) on ESA's Mars Express spacecraft, which are oriented at an angle with respect to the planet's surface. A valley-shaped depression in Phlegra Montes has been level filled; on the surface of infill, parallel-running flow patterns can be seen. In the foreground, an elongated hill is visible, partially surrounded by similar flow patterns. It is conceivable that rock glaciers – bodies of ice interspersed with boulders and rocky debris – slowly moving across the surface of the planet created these patterns.

Credit: ESA/DLR/FU Berlin (G. Neukum).

Realistic perspective views of the Martian surface can be generated from data acquired by the stereo and colour channels of the High Resolution Stereo Camera (HRSC) on ESA's Mars Express spacecraft, which are oriented at an angle with respect to the planet's surface. In the centre of the image, a depression can be seen between the chains of hills in Phlegra Montes, into which material with plastic properties has flowed – presumably from higher altitude regions – partially filling it. In general, the material appears to have moved downslope from the chains of hills; 'lobate debris aprons' have formed at the downstream end. The mountains in the foreground are about 2000 metres high.

Credit: ESA/DLR/FU Berlin (G. Neukum).

Phlegra Montes is a mountainous massif that stretches for several hundreds of kilometres to the northeast of the Elysium volcanic region. It forms the boundary between Utopia Planitia to the west and Arcadia Planitia to the east. ESA's Mars Express spacecraft flew over the region on 1 June 2011 at an altitude of around 400 kilometres during orbit 9465, and the HRSC instrument on ESA’s Mars Express spacecraft imaged a long strip. The images in this article are located in the framed area, covering a region around 73 kilometres wide and 140 kilometres long – some ten thousand square kilometres or roughly the size of the Tyrol.

Credit: NASA/JPL (MOLA) / FU Berlin.

Digital terrain models can be generated using data acquired by several of the nine channels of the High Resolution Stereo Camera (HRSC) on ESA's Mars Express spacecraft, which image the planetary surface from different angles. The use of false colours enables the topography to be pictorially represented – the elevation scale is at the top left of the image; north is to the right. In the absence of 'sea level', the elevation data is referenced to an areoid – a modelled equipotential surface on which everything experiences the same gravitational attraction towards the centre of the planet. The Phlegra Montes mountain chain running diagonally through the image is elevated some 2000 to 3000 metres above the surrounding Elysium and Arcadia Planitiae. In general, material forming the distinct flow patterns in the valley at the centre of the image – but which is also found in other depressed areas – appears to have moved from the hills towards the lower-lying regions.

Credit: ESA/DLR/FU Berlin (G. Neukum).

Anaglyph images can be created using data from the nadir channel of the High Resolution Stereo Camera (HRSC) camera system, the field of view of which is which is directed vertically down onto the Martian surface, and one of the four stereo channels, which are directed obliquely towards the surface. By using red/blue (cyan) or red/green glasses, a three-dimensional impression of the landscape is obtained; north is to the right in the image. The numerous rounded, one- to two-thousand-metre high hills and the ridges of Phlegra Montes are striking. Similarly the rims of a number of fresh – and therefore younger – impact craters are clearly elevated above their environs. More subtle, but still easy to recognise, are small differences in altitude that have been caused by the flow of material. Flow patterns with thin, mostly parallel-running rilles can be seen, as can numerous 10-metre-high flow fronts, the lobate tongues of which hint at large-scale material transportation. Several impact craters have been partially filled by this process as well. The flow patterns bear a strong similarity to the surfaces of 'rock glaciers' on Earth.

Credit: ESA/DLR/FU Berlin (G. Neukum).

The nadir channel, the field of view of which is which is directed vertically down onto the Martian surface, enabled the High Resolution Stereo Camera (HRSC) camera system to acquire image data with a resolution of 16 metres per pixel as Mars Express flew over the Phlegra Montes region during orbit 9465. This enables small-scale geological structures to be identified. To improve the depiction, the resolution in the images shown here has been slightly reduced; north is to the right. The flow patterns in the depressions in this mountainous region, originating from mass transportation of plastically deforming material, are particularly striking. Large volumes of rocky material appear to have moved along the topographical slope, flowing around obstructions such as hills and filling low-lying areas. Such mass transportations are probably the result of 'rock glaciers'– bodies of ice interspersed with boulders and rocky debris that also occur on Earth, primarily in regions of permafrost on high mountain ranges or at polar latitudes. It is conceivable that rock glaciers slowly moving across the surface of the planet created these flow patterns.

Credit: ESA/DLR/FU Berlin (G. Neukum).