20. July 2022
Mars Express mission

Un­equal sib­lings: Ius and Titho­ni­um Chas­ma

Perspective view of Tithonium and Ius Chasma from the northwest
Per­spec­tive view of Titho­ni­um and Ius Chas­ma from the north­west
Image 1/8, Credit: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

Perspective view of Tithonium and Ius Chasma from the northwest

Ex­ten­sion­al tec­ton­ic ac­tiv­i­ty pro­duced the two rift frac­tures of Titho­ni­um Chas­ma (left) and Ius Chas­ma (right). Due to the space open­ing as the crust ex­pand­ed to the north (left) and south, re­spec­tive­ly, crustal blocks in the Sinai Planum plateau slumped. The orig­i­nal sur­face of the plateau can be seen in the cen­tre of the im­age. De­pres­sions run­ning in a straight line in­di­cate that the tec­ton­ic stress un­der which the re­gion was sub­ject­ed al­so left its mark on the al­most in­tact plateau.
Vertical plan view of Ius and Tithonium Chasma
Ver­ti­cal plan view of Ius and Titho­ni­um Chas­ma
Image 2/8, Credit: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

Vertical plan view of Ius and Tithonium Chasma

The two rift val­leys of Ius and Titho­ni­um Chas­ma, up to 7000 me­tres deep, form the west­ern part of the east-to-west run­ning part of Valles Mariner­is, the largest rift val­ley in the So­lar Sys­tem, which is al­to­geth­er 3800 kilo­me­tres long. The two chas­ma­ta ex­tend a to­tal of 800 and 840 kilo­me­tres, re­spec­tive­ly. North is on the right in the im­age. The im­age sec­tion is ap­prox­i­mate­ly 300 by 110 kilo­me­tres, which is rough­ly the size of the Ger­man state of Bran­den­burg. There are strik­ing dif­fer­ences be­tween the two struc­tures: where­as in Ius Chas­ma (left) ma­te­ri­al pri­mar­i­ly from land­slides cov­ers the floor of the rift val­ley, in Titho­ni­um Chas­ma it is dark sands of vol­canic ori­gin trans­port­ed there by the wind that char­ac­terise the land­scape.
Localisation aid for the landscapes described in the text
Lo­cal­i­sa­tion aid for the land­scapes de­scribed in the text
Image 3/8, Credit: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

Localisation aid for the landscapes described in the text

The three ar­rows at the top cen­tre of the im­age in­di­cate the view­ing di­rec­tions of the per­spec­tive views of Ius and Titho­ni­um Chas­ma. North is to the right in the im­age.From left to right: par­al­lel scarps; mass wast­ing; small land­slide; dark dunes; erod­ed land­slide; mound 1 and mound 2; land­slide; small­er land­slides.
A hill approximately 3000 metres tall in Tithonium Chasma
A hill ap­prox­i­mate­ly 3000 me­tres tall in Titho­ni­um Chas­ma
Image 4/8, Credit: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

A hill approximately 3000 metres tall in Tithonium Chasma

A light-coloured hill in the mid­dle of Titho­ni­um Chas­ma, more than 3000 me­tres tall, fea­tures a sur­face heav­i­ly erod­ed by the wind. These are 'ero­sion chan­nels', known yardan­gs. The ma­te­ri­al that forms these dome-shaped hills is less re­sis­tant to ero­sion com­pared to the sur­round­ing rocks. Thus, the wind has been able to sand these fur­rows out of the rock with the sand and dust par­ti­cles it car­ries, sim­i­lar to a sand­blast­ing fan.
Volcanic sand deposits
Vol­canic sand de­posits
Image 5/8, Credit: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

Volcanic sand deposits

In this per­spec­tive view of Titho­ni­um Chas­ma, the sur­round­ing ar­eas are cov­ered by a thin lay­er of dark sand (shown bluish in these con­trast-en­hanced im­ages), which al­so forms im­pos­ing dark dunes in the cen­tral part of Titho­ni­um Chas­ma (seen in plan view). Due to the prox­im­i­ty of the Thar­sis vol­canic re­gion to the west, many of the rocks present in this area con­sist of lay­ers of la­va flows and vol­canic ash that have been erod­ed and are the source of the black-grey sands that make up the dunes. Min­er­alog­i­cal stud­ies of the dune ma­te­ri­al con­firmed their vol­canic ori­gin.
Regional overview of the west of Valles Marineris
Re­gion­al overview of the west of Valles Mariner­is
Image 6/8, Credit: NASA/JPL-Caltech/MOLA; FU Berlin

Regional overview of the west of Valles Marineris

The scenes shown here were tak­en on 21 April 2022 us­ing the DLR-de­vel­oped HRSC stereo cam­era on ESA's Mars Ex­press space­craft dur­ing or­bit 23,123. The elon­gat­ed rect­an­gle shows the en­tire im­age strip. The im­ages shown here were tak­en from with­in this small rect­an­gle. The im­age res­o­lu­tion is 25 me­tres per pix­el. The cen­tre of the im­age is at about 272 de­grees east and 6 de­grees south. Ius and Titho­ni­um Chas­ma form the west­ern part of the Valles Mariner­is rift val­ley, which is 3800 kilo­me­tres long in to­tal.
Anaglyph image of Tithonium and Ius Chasma
Anaglyph im­age of Titho­ni­um and Ius Chas­ma
Image 7/8, Credit: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

Anaglyph image of Tithonium and Ius Chasma

So-called anaglyph im­ages can be gen­er­at­ed from the nadir chan­nel of the DLR-de­vel­oped HRSC cam­era sys­tem on ESA's Mars Ex­press space­craft, 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 al­low a three-di­men­sion­al view of the land­scape. The to­pog­ra­phy is clear­ly vis­i­ble. There is an al­ti­tude dif­fer­ence of about 7000 me­tres be­tween the plateau in the cen­tre of the pic­ture and the two rift val­leys to the north and south. North is to the right in the im­age.
Topographic image map of Ius and Tithonium Chasma
To­po­graph­ic im­age map of Ius and Titho­ni­um Chas­ma
Image 8/8, Credit: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

Topographic image map of Ius and Tithonium Chasma

The DLR-de­vel­oped HRSC stereo cam­era on ESA's Mars Ex­press space­craft us­es its nine sen­sors ar­ranged trans­verse­ly to the di­rec­tion of flight to take im­ages of the plan­et from var­i­ous an­gles and in colour. From the stereo chan­nels that look oblique­ly at the sur­face and the nadir chan­nel that points per­pen­dic­u­lar­ly at Mars, teams of re­searchers at the DLR In­sti­tute of Plan­e­tary Re­search and the Freie Uni­ver­sität Berlin pro­duce dig­i­tal ter­rain mod­els that as­sign el­e­va­tion in­for­ma­tion to each pix­el. The dif­fer­ences in al­ti­tude can be read from the colour scale at the top right of the im­age. There is an al­ti­tude dif­fer­ence of more than 7000 me­tres be­tween the high­est re­gions (light pink) and the low­est points in the two chas­ma­ta (deep blue) – all the moun­tains of the South Amer­i­can An­des, in­clud­ing Aconcagua, which is 6961 me­tres high, could be ‘hid­den’ there be­low the top of the ter­rain.
  • Two scenically different tectonic rifts form the western part of the great fault structure of Valles Marineris.
  • On the plateau of the Sinai Plain, Tithonium Chasma, up to 7000 metres deep and running from east to west, drops abruptly.
  • Parallel to this, further north, runs the equally deep Ius Chasma, which features traces of numerous landslides.
  • Focus: Space, Solar System exploration, Mars, DLR HRSC stereo camera

When NASA's Mariner 9 spacecraft reached Mars more than 50 years ago at the end of 1971 and began to explore the planet from orbit, there was initially great disappointment at the control centre: virtually nothing could be seen in the images sent to Earth. At that time, a global dust storm was raging on Mars, which made it impossible to see the surface. Only the peaks of the highest volcanoes stood out from the monotonous grey. In early 1972, the weather improved, the dust settled and the mission began to take a global survey of Mars. One of the most impressive structures observed was a rift valley up to 10 kilometres deep and roughly 3800 kilometres long – as long as the distance from the United States' east to west coast or from North Cape to Sicily. In honour of the mission, the extensive system of this structure, torn open by tectonic forces, was named Valles Marineris – 'the valleys of Mariner'. The images shown here, acquired using the DLR-developed High Resolution Stereo Camera (HRSC) on board ESA's Mars Express spacecraft, show sections of two elongated valleys in the west of Valles Marineris: Ius Chasma and Tithonium Chasma.

Tithonium Chasma measures approximately 800 kilometres from east to west and Ius Chasma 840 kilometres. To the west, the rugged region of Noctis Labyrinthus adjoins the two valleys, and to the east, the central depressions of Melas and Candor Chasma, which open further to the north. The term chasma has been designated by the International Astronomical Union to describe an elongated depression with steep slopes on the sides. In the images presented here, the greatest differences in elevation from the plateau to the lowest regions within the chasmata reach more than 7000 metres. The plan view colour image shows Ius Chasma on the left (south) and Tithonium Chasma on the right (north). The plateau regions around and between the chasmata clearly show the linear, large fractures that were involved in the formation of Valles Marineris.

Dunes of black volcanic sand

There are clear differences between the two valleys. For example, the bottom of Tithonium Chasma is much darker. On closer inspection, dark dunes can be seen at the top of the image (northwest, roughly in the middle of the gorge), and the surrounding areas are also covered by a thin layer of dark sands(shown in bluish in these contrast-enhanced images). Due to the proximity of the Tharsis volcanic region to the west, many of the rocks present in this area consist of layers of lava flows and volcanic ash, which may be the source of the dark coloured sands that make up the dunes. Mineralogical studies of the dune material confirmed their volcanic origin.

Valles Marineris – the largest canyon in the Solar System
Valles Marineris – the largest canyon in the Solar System
This image shows Valles Marineris just east of Ius and Tithonium Chasma, which would connect on the left.
Credit: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO
Another very interesting feature is the two lighter-coloured mountains – one directly opposite the dark dune field and cut from the edge of the picture and the other in the middle of this part of Tithonium Chasma. They are over 3000 metres high and their surfaces have been heavily eroded by the wind. These 'erosion channels' are called yardangs and indicate that the material forming these dome-shaped hills is less resistant to erosion compared to the surrounding rocks, and so the wind has been able to carve these landforms out of the rock with the sand and dust particles it carries. These furrows even reveal that the wind direction of this sand blast was from north-east to south-west (bottom right to top centre in the picture). The soil between the two lighter deposits shows peculiar small nodules, probably made of the same material as the mounds. Spectroscopic studies indicate high concentrations of hydrous sulphate minerals in these layers. Many scientists believe that these deposits were formed by evaporation at a time when the chasmata were filled with water. However, this formation scenario is still the subject of intense debate in the scientific community.

Landslides of enormous magnitude

In the north-east of this wind-swept, light-coloured mountain, enormous deposits of landslides can be seen that had detached themselves from the steep slopes. The larger one is from the break-off of the canyon wall to the northeast (below the hill) and looks relatively young as it has divergent striations and apron-like lobes at its outlet. It is also overlain by smaller landslides in the lower part of the image. This is best seen in the colour-coded digital terrain model. Another large landslide is located to the south (left) of the central hill. However, this looks much more eroded and may therefore be older. Landslides also occur in topographically higher regions, as shown by the 'small' 15-kilometre-wide deposit near the breached crater rim in the central part of the image.

The valley floor in Ius Chasma is just as spectacular. In the undulating and rutted surface, large boulders tilted backwards seem to trace the direction of movement of landslides from the slopes towards the centre of the rift valley. Interestingly, the southern (left) flank of Ius Chasma shows several parallel scarps in a similar east-west orientation as the chasmata and faults themselves. Thus, the north-south orientation of the extensional tectonics that caused the rift to break open is documented in the deposits on the Chasma floor.

Image processing

These HRSC images were taken on 21 April 2022 during orbit 23,123 of ESA's Mars Express spacecraft around Mars. The image resolution is 25 metres per pixel. The centre of the image is at approximately 272 degrees east and 6 degrees south. The colour view (image 1) was created from the nadir channel directed perpendicular to the surface of Mars and the colour channels of the HRSC, the perspective oblique views (images 2, 4) were calculated from the stereo channels of the HRSC. The anaglyph image (image 5), which gives a three-dimensional impression of the landscape when viewed with red-blue or red-green glasses, was derived from the nadir channel and a stereo channel. The top view encoded in rainbow colours (Figure 6) 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 an equipotential surface of Mars (areoid). The systematic processing of the camera data was carried out at the DLR Institute of Planetary Research. Staff from the Department of Planetary Sciences and Remote Sensing at the Freie Universität Berlin used the data to create the image products shown here.

The HRSC experiment on Mars Express

The High Resolution Stereo Camera (HRSC) was developed at the German Aerospace Center (DLR) and built in cooperation with industrial partners (EADS Astrium, Lewicki Microelectronic GmbH and Jena-Optronik GmbH). The science team, led by Principal Investigator (PI) Dr Thomas Roatsch of the DLR Institute of Planetary Research, consists of 52 co-investigators from 34 institutions and 11 nations. The camera is operated by the DLR Institute of Planetary Research in Berlin-Adlershof.

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

Contact
  • Elke Heinemann
    Ger­man Aerospace Cen­ter (DLR)

    Com­mu­ni­ca­tions and Me­dia Re­la­tions
    Telephone: +49 2203 601-2867
    Linder Höhe
    51147 Cologne
    Contact
  • Ulrich Köhler
    Ger­man Aerospace Cen­ter (DLR)
    In­sti­tute of Plan­e­tary Re­search
    Rutherfordstraße 2
    12489 Berlin
    Contact
  • Daniela Tirsch
    Ger­man Aerospace Cen­ter (DLR)
    In­sti­tute of Plan­e­tary Re­search
    Rutherfordstraße 2
    12489 Berlin
    Contact
  • Thomas Roatsch
    Ger­man Aerospace Cen­ter (DLR)
    In­sti­tute of Plan­e­tary Re­search
    Rutherfordstraße 2
    12489 Berlin
    Contact
DLR newsletter

Newslet­ter

Stay up to date and sub­scribe to the DLR newslet­ter with ar­ti­cles from the DLR ed­i­to­ri­al team in Ger­man and En­glish.

Related news

Main menu