The joint ESA and Russian ExoMars rover’s top priority is to search the Martian surface for signs of life, past or present, and scientists think they know just the spot where – if life ever existed or exists on Mars – it might be found. Today the ExoMars team announced that the equatorial region named Oxia Planum has been recommended as the primary candidate for the landing site.
“Our preliminary analysis shows that Oxia Planum appears to satisfy the strict engineering constraints while also offering some very interesting opportunities to study, in situ, places where biosignatures might best be preserved,” said Jorge Vago, ESA’s project scientist.
The rover is currently scheduled to launch in 2018 and land on Mars in 2019, but the timetable is still under review, depending on any issues with construction of the rover. While the final landing site won’t be selected by both ESA and Roscosmos until six months before launch, this recommendation will weigh heavily in the decision.
Some of the priority requirements for the landing site is that is must show abundant morphological and mineralogical evidence for long-duration, or frequently reoccurring water activity, and that there should be numerous sedimentary rock outcrops.
From orbital study by previous missions, Oxia Planum is known to contain clays, and there appears to be remnants of a possible fan or delta, as seen in the image above from the HiRISE camera on the Mars Reconnaissance Orbiter. This would be one of the potential science targets.
The site selection process has been under way since late 2013, when the science community was asked to propose candidates. In October 2014, four candidates were chosen by the Landing Site Selection Working Group. Now this month, October 2015, the same group met to determine two candidate sites that conform best to both the engineering constraints of descent and landing, and the best possible scientific return of the mission. But their preference for now is Oxia Planum. The team will continue to debate the merits and safety of the proposed sites.
ESA said that all four sites that have been under study – Aram Dorsum, Hypanis Vallis, Mawrth Vallis and Oxia Planum – show evidence of having been influenced by water in the past, and are likely representative of global processes operating in the Red Planet’s early history.
Additionally, all locations offer the opportunity of landing at a scientifically interesting site or finding one within a 1 km drive from the touchdown point, with numerous targets accessible along a typical 2 km traverse planned for the mission of 218 martian days (each 24 hours 37 minutes).
The ExoMars mission is a dual mission with one part launching in 2016 (the Trace Gas Orbiter plus an Entry, Descent and Landing Demonstrator Module) and the rover tentatively scheduled to launch in 2018. As final site selection comes closer, the scientists involved with the mission are anticipating the mission.