Observations

Coordination of WP1: S. Rodriguez (AIM)

 

In the solar system, a great diversity of aeolian dunes depending on the planetary environment and climate can be found: siliclastic, basaltic, gypseous, icy, hydrocarboneous dunes. Despite different ranges of atmospheric pressures, temperatures, fluid composition and gravity, many of the dunes on extraterrestrial surfaces share a number of similarities in shape with those on Earth, although they can show some notable differences in scale and sedimentary composition.

WP1 aims at exploring and characterizing the planetary environments and dune characteristics on Mars and Titan, and in specific regions on Earth which are considered as relevant analogues. The main targets of WP1 are thus:

  • basaltic, gypseous and icy dunes on Mars: Tasks 1.M.1 and 1.M.2.
  • hydrocarboneous dunes on Titan (Task 1.T).
  • siliclastic and icy dunes on Earth (Task 1.E.1 and 1.E.2).

The plethora of data returned from recent planetary missions has enabled a new era in planetary geomorphic studies. Planetary dunes will be studied: (i) on Mars using the visible and infrared images and spectro-images acquired during the past Mars Global Surveyor (MGS) mission and the ongoing Mars-Express (MeX) and Mars Reconnaissance Orbiter (MRO) missions (Tasks 1.M.1 and 1.M.2), and (ii) on Titan using the VIMS infrared spectro-images and the RADAR images from the ongoing Cassini-Huygens mission (Tasks 1.T). The partners involved in WP1 all have full access to those data. Besides, a lot of planetary images are now publicly available.

 

On Earth, in addition to the analysis of aerial and satellites images from ENVISAT-LANDSAT-SPOT, field surveys are planned in order to study siliclastic dunes in China (Tengger desert and Qaidam basin – Task 1.E.1 – Figure 1) and icy dunes in the French Alps (Mont-Blanc Massif – Task 1.E.2).

Jointly to the individual objectives presented here, one of the major objectives of WP1 is foremost to construct a comprehensive database for Mars and Titan dunes thanks to the effort of all collaborators involved in the planetary dunes observations. This database will complement the documentation on Martian dunes, and will incorporate a new and exhaustive documentation on Titan’s dunes. This database will benefit, as it will be gradually filled out, to the experimental (WP2) and modeling (WP3) researches of our project, but also, at the term of the project, to the entire planetary dunes community. We intend to make the dune database user-friendly and available online to the international community (for details on the database, see Sections 2.3 and 4).

 

It is also worth noting that the observation of Mars and Titan will be pursued during the duration of the EXO-DUNES project, bringing a constant flux of new images and improving the coverage of the planetary dune fields. Indeed, exploration programs for Mars are already set up for the next 5 years and the Cassini-Huygens mission has been extended until May 2017, which is particularly timely for our project.

 

Maj : 16/07/2014 (4)

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