30. March 2022
Mars Express mission

Frozen beau­ty in north­ern Mars

Vertical plan view of a section of Utopia Planitia
Ver­ti­cal plan view of a sec­tion of Utopia Plani­tia
Image 1/6, Credit: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

Vertical plan view of a section of Utopia Planitia

The pe­ri­od­ic tilt­ing of the plan­et's ax­is of ro­ta­tion by up to 60 de­grees caus­es strong fluc­tu­a­tions in the Mar­tian cli­mate. Even in tem­per­ate lat­i­tudes, which on Earth would cor­re­spond to ge­o­graph­ic re­gions such as Eu­rope, this tilt­ing means that ice is de­posit­ed over long pe­ri­ods of time. To­geth­er with the dust car­ried in by the wind, the ice forms lay­ers that cov­er ex­ist­ing sur­face for­ma­tions like a cloak. In this con­trast-en­hanced aeri­al view, these 'man­tle de­posits' can be seen on the left and right thirds of the im­age (north is on the right of the im­age). Crater ejec­ta cov­ers the area in two lay­ers to the left and right of the two 10- and 12-kilo­me­tre im­pact craters in the cen­tre of the im­age. Man­tle de­posits can be seen on the crater rims and are par­tic­u­lar­ly clear in­side the im­pact craters. Here, it is re­ferred to as 'con­cen­tric crater fill' and is al­so found in the small­er craters in the area.
Oblique perspective view from the east
Oblique per­spec­tive view from the east
Image 2/6, Credit: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

Oblique perspective view from the east

Dig­i­tal ter­rain mod­els gen­er­at­ed us­ing da­ta ac­quired by the stereo im­age chan­nels of the HRSC cam­era sys­tem on ESA's Mars Ex­press or­biter can be used to cre­ate per­spec­tive views of the Mar­tian land­scape. Sub­tle dif­fer­ences in ma­te­ri­al and tex­ture have been made more ap­par­ent by en­hanc­ing the con­trast in the colour da­ta. The two im­pact craters in the cen­tre of the im­age, which mea­sure 10 and 12 kilo­me­tres across, show a dou­ble-lay­ered blan­ket of ejec­ta. On clos­er in­spec­tion, in­di­vid­u­al lay­ers of man­tle de­posits can be seen on the slopes of the many small­er de­pres­sions on the left of the im­age, where ero­sion has breached the pre­vi­ous­ly closed man­tle cov­er­ing. The crater in­fill, which is al­so lay­ered, in­di­cates a mix­ture of ice and dust that has col­lapsed in the mid­dle of the crater, giv­ing it a con­cen­tri­cal­ly lined sur­face tex­ture.
Oblique perspective view from the northwest
Oblique per­spec­tive view from the north­west
Image 3/6, Credit: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

Oblique perspective view from the northwest

Dig­i­tal ter­rain mod­els gen­er­at­ed us­ing da­ta ac­quired by the stereo im­age chan­nels of the HRSC cam­era sys­tem on ESA's Mars Ex­press or­biter can be used to cre­ate per­spec­tive views of the Mar­tian land­scape. Sub­tle dif­fer­ences in ma­te­ri­al and tex­ture have been made more ap­par­ent by en­hanc­ing the con­trast in the colour da­ta. In the 12-kilo­me­tre crater in the fore­ground, the cloak of dust and for­mer ice cov­er­ing the ter­rain shows a typ­i­cal tex­ture of sin­u­ous, con­cen­tri­cal­ly de­formed de­posits. Over time, it has formed curved de­pres­sions through grad­u­al age­ing and ero­sion, in­clud­ing through the di­rect evap­o­ra­tion of ice.
Utopia in Mars' northern hemisphere
Utopia in Mars' north­ern hemi­sphere
Image 4/6, Credit: NASA/JPL-Caltech/MOLA; FU Berlin

Utopia in Mars' northern hemisphere

Utopia is one of the three ma­jor to­po­graph­i­cal de­pres­sions in Mars' north­ern low­lands. This im­pact basin, which mea­sures 3300 kilo­me­tres across, has been filled with sed­i­ment, la­va and some­times ice over the last four bil­lion years. The High Res­o­lu­tion Stereo Cam­era (HRSC) op­er­at­ed by the Ger­man Aerospace Cen­ter (DLR) on board ESA's Mars Ex­press or­biter ac­quired the im­age strip on 12 Ju­ly 2021. The land­scapes pre­sent­ed here are lo­cat­ed in the small, in­ner rect­an­gle, which is ap­prox­i­mate­ly 90 by 200 kilo­me­tres.
Topographical map of part of Utopia Planitia
To­po­graph­i­cal map of part of Utopia Plani­tia
Image 5/6, Credit: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

Topographical map of part of Utopia Planitia

DLR's High Res­o­lu­tion Stereo Cam­era (HRSC) on ESA's Mars Ex­press or­biter ac­quires im­ages of the Mar­tian sur­face at dif­fer­ent an­gles and with four colour chan­nels us­ing its nine sen­sors, which are each ori­ent­ed across the line of flight. From the four stereo chan­nels look­ing at an an­gle and the nadir chan­nel point­ing per­pen­dic­u­lar­ly at Mars, teams of sci­en­tists at the DLR In­sti­tute of Plan­e­tary Re­search and Freie Uni­ver­sität Berlin com­pute dig­i­tal ter­rain mod­els that as­sign el­e­va­tion in­for­ma­tion to each pix­el. The colour scale at the top right of the im­age shows the dif­fer­ences in al­ti­tude in the re­gion. These are not very pro­nounced in the Utopia low­lands of the north­ern hemi­sphere; there is on­ly a 400-me­tre al­ti­tude dif­fer­ence be­tween the low­est ar­eas, coloured blue, and the high­est crater rims in the cen­tre of the im­age, coloured grey. The al­most cir­cu­lar, dark-blue de­pres­sion to the right of the im­age cen­tre in­di­cates a very old crater that has been al­most com­plete­ly oblit­er­at­ed by ero­sion. North is to the right of the im­age.
Anaglyph image of Utopia Planitia
Anaglyph im­age of Utopia Plani­tia
Image 6/6, Credit: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

Anaglyph image of Utopia Planitia

Anaglyph im­ages can be gen­er­at­ed us­ing da­ta ac­quired by the nadir chan­nel of the DLR-op­er­at­ed HRSC cam­era sys­tem on board ESA's Mars Ex­press or­biter, the field of view of which is di­rect­ed per­pen­dic­u­lar­ly to the sur­face of Mars, and one of the four oblique stereo chan­nels. When used with red-blue or red-green glass­es, they pro­vide a three-di­men­sion­al view of the land­scape. North is to the right in this im­age. The to­pog­ra­phy of the land­scape – the dif­fer­ences in the height of the sur­face for­ma­tions shaped by ice and wind – can be seen more clear­ly here than in the coloured plan view, in par­tic­u­lar the thermokarst tex­tures of the in­fill in the two 12- and 10-km craters in the cen­tre of the im­age.
  • Ice has shaped the landscapes of Mars' vast northern lowlands.
  • These regions are the legacy of a time when Mars' axis of rotation was much more inclined than it is today, leading to extreme climate fluctuations.
  • These images of a landscape in Utopia Planitia were acquired by the DLR-developed HRSC stereo camera during orbit 22,150 of ESA's Mars Express spacecraft.
  • The HRSC has been mapping Mars at high resolution, in three dimensions and in colour since 2004.
    The data that it provides are an important resource for Mars research both now and in the future.
  • Focus: Space exploration, planetary research, Mars

These images were created using data acquired by the High Resolution Stereo Camera (HRSC), which was developed at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) and is operated by the DLR Institute of Planetary Research in Berlin-Adlershof. They show a landscape in Utopia Planitia that is millions of years old and was shaped by ice. Utopia is one of three major topographical depressions in the northern hemisphere of Mars and measures 3300 kilometres across. The basin was probably created approximately four billion years ago by the impact of an asteroid that may have been over 200 kilometres in diameter. Over time, the impact basin, which was initially several kilometres deep, has filled up with sediments and ice that were transported there by wind and water, as well as with lava from low-viscosity volcanic eruptions. In the area of Utopia shown here, it is primarily thick layers of ice and dust that have blanketed the existing topography, creating this almost impressionistic landscape.

Utopia – based on an ancient Greek term meaning 'no place' or 'nowhere', or a place that exists only in the imagination – is the largest recognised impact basin on Mars; larger even than the far more striking impact formation Hellas Planitia in the southern highlands. NASA's Viking 2 spacecraft landed in Utopia on 3 September 1976, a few hundred kilometres to the east of the landscape shown here. Alongside its sister spacecraft Viking 1, which landed in Chryse Planitia, it explored Mars for three and a half years. These were the first spacecraft to conduct such missions on the Martian soil. During the winter, Viking 2 transmitted images to Earth showing rocks covered with hoarfrost after cold nights – which caused a scientific sensation at the time.

'Tilted Mars' – an ice machine

There was probably much more ice in Utopia Planitia 10 million years ago, as the planet's axis of rotation was tilted much more back then, leading to cyclical changes in the Martian climate. Unlike Earth, Mars' inclination changes significantly on timescales ranging from hundreds of thousands to millions of years. The inclination of Mars' axis of rotation today, at 25.2 degrees (compared to Earth’s 23.3 degrees), means that ice is present in relatively modest amounts at the north and south poles. Ten million years ago, however, the axis could have been tilted as much as 60 degrees from the orbital plane, resulting in much more extreme climate variability – with ice in Utopia Planitia being one of the consequences.

This resulted in the mantled deposits shown here. These are thick, ice- and dust-rich layers thought to have been deposited 10 million years ago as snow mixed with wind-blown dust. This mixture of dust and ice covers and smooths out the surface like a cloak. This can be seen very well in the large patches on the left and right of the vertical plan view (Image 1). The two impact craters in the centre of the image, which measure 10 and 12 kilometres across, show a double-layered blanket of ejecta. On closer inspection, the stratified appearance of the mantle deposits can be seen at the crater rims and particularly well inside the impact craters. Here it is referred to as 'concentric crater fill' and is also found in the smaller craters in the area.

Shrinkage cracks filled with dark dust

The second largest crater in the centre of the images shows a typical texture of sinuous, concentrically deformed deposits on the mantle cover, vaguely reminiscent of a brain. They developed curved indentations through gradual ageing and erosion, including through the direct evaporation of ice. A pattern is faintly visible in the dark-coloured regions just to the right of this crater. This was formed when the surface cracked due to cooling and thermal contraction, leaving a polygonal pattern in the ground. Dark, wind-blown dust deposited in the cracks is responsible for the dark colouring of this region.

Curved, sediment-filled depressions are visible throughout the image. These can be circular to elliptical and measure anywhere from a few tens of metres to several kilometres in size and be up to tens of metres deep. They are the result of the melting or evaporation of ice underground, followed by the collapse of the surface. The process of subsidence due to ice loss in the subsurface is referred to as thermokarst.

A closer look reveals stratification of the mantle deposits in and around the curved depressions. Radar measurements, which can detect layer boundaries between ice lenses and rock, and spectrometry, which can measure the abundance of hydrogen, have detected water ice in the soil of the northern lowlands. This has been confirmed by NASA's Phoenix lander (2009). Ice has been discovered at greater depths by observations of fresh impact craters and depressions, and also in numerous other locations using radar soundings.

Image processing

These images were created using data acquired by the High Resolution Stereo Camera (HRSC) on 12 July 2021 during Mars Express orbit 22,150. The image resolution is approximately 19 metres per pixel. The centre of the image is located at approximately 83 degrees east and 43 degrees north. The colour plan view was created using data acquired by the nadir channel, the field of view of which is aligned perpendicular to the surface of Mars, and the colour channels of HRSC. The oblique perspective views were computed using a terrain model and data from the HRSC nadir and colour channels. The colour-coded topographic view is based on a Digital Terrain Model (DTM) of the region from which the topography of the landscape can be derived. The reference body for the HRSC DTM is a Martian equipotential surface (Areoid). The systematic processing of the camera data was carried out at the DLR Institute of Planetary Research in Berlin-Adlershof. Personnel in the Department of Planetary Sciences and Remote Sensing at Freie Universität Berlin used these data to create the image products shown here.

The HRSC experiment on Mars Express

The High Resolution Stereo Camera (HRSC) was developed by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) and built in collaboration with partners in industry (Airbus, Lewicki Microelectronic GmbH and Jena-Optronik GmbH). The science team, which is headed by Principal Investigator (PI) Thomas Roatsch, consists of 50 co-investigators from 34 institutions in 11 countries.

All images in high resolution and more images acquired by the HRSC instrument can be found in the Mars Express image gallery on flickr.

Contact
  • Elke Heinemann
    Ger­man Aerospace Cen­ter (DLR)

    Com­mu­ni­ca­tions and Me­dia Re­la­tions
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    Ger­man Aerospace Cen­ter (DLR)
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  • Ulrich Köhler
    Ger­man Aerospace Cen­ter (DLR)
    In­sti­tute of Plan­e­tary Re­search
    Rutherfordstraße 2
    12489 Berlin
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  • Thomas Roatsch
    Ger­man Aerospace Cen­ter (DLR)
    In­sti­tute of Plan­e­tary Re­search
    Rutherfordstraße 2
    12489 Berlin
    Contact
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