[meteorite-list] Four Candidate Landing Sites for ExoMars 2018

[Ron Baalke]

http://www.esa.int/Our_Activities/Space_Science/Four_candidate_landing_sites_for_ExoMars_2018

Four Candidate Landing Sites for ExoMars 2018
European Space Agency
1 October 2014

Four possible landing sites are being considered for the ExoMars mission 
in 2018. Its rover will search for evidence of martian life, past or present.

ExoMars is a joint two-mission endeavour between ESA and Russia's Roscosmos 
space agency. The Trace Gas Orbiter and an entry, descent and landing 
demonstrator module, Schiaparelli, will be launched in January 2016, arriving 
at Mars nine months later. The Rover and Surface Platform will depart 
in May 2018, with touchdown on Mars in January 2019.

The search for a suitable landing site for the second mission began in 
December 2013, when the science community was asked to propose candidates.

The eight proposals were considered during a workshop held by the Landing 
Site Selection Working Group in April. By the end of the workshop, there 
were four clear front-runners.

Following additional review by an ESA-appointed panel, the four sites 
have now been formally recommended for further detailed analysis.

The sites - Mawrth Vallis, Oxia Planum, Hypanis Vallis and Aram Dorsum 
- are all located relatively close to the equator.

"The present-day surface of Mars is a hostile place for living organisms, 
but primitive life may have gained a foothold when the climate was warmer 
and wetter, between 3.5 billion and 4 billion years ago," says Jorge Vago, 
ESA's ExoMars project scientist.

"Therefore, our landing site should be in an area with ancient rocks where 
liquid water was once abundant. Our initial assessment clearly identified 
four landing sites that are best suited to the mission's scientific goals."

The area around Mawrth Vallis and nearby Oxia Planum contains one of the 
largest exposures of rocks on Mars that are older than 3.8 billion years 
and clay-rich, indicating that water once played a role here. Mawrth Vallis 
lies on the boundary between the highlands and lowlands and is one of 
the oldest outflow channels on Mars.

The exposed rocks at both Mawrth Vallis and Oxia Planum have varied compositions, 
indicating a variety of deposition and wetting environments. In addition, 
the material of interest has been exposed by erosion only within the last 
few hundred million years, meaning the rocks are still well preserved 
against damage from the planet's harsh radiation and oxidation environment.

By contrast, Hypanis Vallis lies on an exhumed fluvial fan, thought to 
be the remnant of an ancient river delta at the end of a major valley 
network. Distinct layers of fine-grained sedimentary rocks provide access 
to material deposited about 3.45 billion years ago.

Finally, the Aram Dorsum site receives its name from the eponymous channel, 
curving from northeast to west across the location. The sedimentary rocks 
around the channel are thought to be alluvial sediments deposited much 
like those around Earth's River Nile. 

This region experienced both sustained water activity followed by burial, 
providing protection from radiation and oxidation for most of Mars’ 
geological history, also making this a site with strong potential for 
finding preserved biosignatures.

While all four sites are clearly interesting scientifically, they must 
also allow for the operational and engineering requirements for safe landing 
and roving on the surface," adds Jorge.

"Technical constraints are satisfied to different degrees in each of these 
locations and, although our preliminary evaluation indicates that Oxia 
Planum has fewer problems compared to the other sites, verification is 
still on going.'

The next stage of analysis will include simulations to predict the probability 
of landing success based on the entry profile, atmospheric and terrain 
properties at each of the candidate sites.

The aim is to complete the certification of at least one site by the second 
half of 2016, with a final decision on the landing site for the ExoMars 
2018 rover to be taken sometime in 2017.

Notes for Editors

Download the full report: Recommendation for the narrowing of ExoMars 
2018 landing sites
http://exploration.esa.int/mars/54707-recommendation-for-the-narrowing-of-exomars-2018-landing-sitesrecommendation-for-the-narrowing-of-exomars-2018-landing-sites/

More ExoMars images, including digital terrain models of the candidate 
landing sites, are available here.
http://exploration.esa.int/mars/44969-images-videos-archive/

For further information, please contact:

Markus Bauer
ESA Science and Robotic Exploration Communication Officer
Tel: +31 71 565 6799
Mob: +31 61 594 3 954
Email: markus.bauer at esa.int

Jorge Vago
ESA ExoMars 2018 project scientist
Scientific Support Office/Directorate of Science and Robotic Exploration
Email: jorge.vago at esa.int