ESA ExoMars landing site on Mars.

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3488

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BBC article here concerning landing sites for future ExoMars Rover.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>
 
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h2ouniverse

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Hi Andrew,<br /><br />I am skeptical of any site close to the equator. (excepted very low terrain e.g. Valles Marineris)<br />It is a pity that, for the first exobio mission since Viking, and the first msission ever able to analyse subsurface (-2m) material, we would go to dry places and/or high terrain...<br /><br />Why not Hellas basin? There is some loss for the Solar Array (not that much if landing site is close to 30°S), but pressure is high (11 mbar). So high that at 0°C water coudl survive. Temperature is lower, but this means that if water has once filled the bottom of the crater, it would have taken far moretime than elsewhere on Mars for it to vaporize, and more likelihood for infiltration in soil. Moreover the Martian crust would have been thinner there, with prospects for more heat from underground.<br /><br />And at least, if nothing of biological interest is found, the bottom of a large impact crater would be chemically studied... <br /><br />Do you know why this is not considered? <br />Regards.
 
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JonClarke

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Why don't you like equatorial sites? <br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>
 
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h2ouniverse

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Apart from Valles Marineris, equatorial sites are high terrain, low pressure, "warm" temperature. So not great places for water ice to lie at just 2m below surface imho. Same for water upwelling from deep veins.<br />Exomars Pasteur payload is really a true bio-lab. It would be a pity if we miss the biotes if they exist. I think we should go where there is most chance to drill into some frozen ice coming from relatively recent upwelling of deep water veins. To get a reasonable probability these veins should be as close as possble to the surface.<br />As we cannot go to the poles, we should find second choices.<br />Valles Marineris is a fluvial valley. The lower terrain there might not have been the local lowest point when water was flowing (then may be not the place for a long-lasting sea to form, the water being evacuated Eastwards then Northwards into Vastitas Borealis).<br /><br />So unless the recent findings of Marsis are for sure linked to water ice (and not ashes), it would seem IMO that the best landing site would be a deep depression like Argyre or Hellas. <br />In particular the piedmont of the Northern Rim of Hellas?<br /><br />Am I missing a point?<br /><br />Regards.
 
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thereiwas

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Elysium *might* have ice, and that is near the equator around 160 degrees longitude. But no proof yet. Hellas sounds like an excellent idea. All sorts of things might have been flushed to the bottom, in addition to the higher air density.
 
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h2ouniverse

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Elysium is tempting indeed. With four reservations:<br />* is this really ice below the dust?<br />* if yes, is it at less than 2m (within reach of Exomars drill)<br />* can it be supplied by deep water, at least from time to time<br />* is the dust rovable?<br /><br />Regards.
 
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JonClarke

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<i>Apart from Valles Marineris, equatorial sites are high terrain, low pressure, "warm" temperature. So not great places for water ice to lie at just 2m below surface imho. Same for water upwelling from deep veins.</i><br /><br />The equatorial regions of Mars are +/- 25 degrees. They include extensive areas below Martian datum and thus can support at least ephemeral moisture. The deepest are Amazonia, Chryse, Isidis, and Elysium Planitia, plus Vallis Marineris. But all the landing sites listed in the BBC article are below datum.<br /><br /><i>Exomars Pasteur payload is really a true bio-lab. It would be a pity if we miss the biotes if they exist. I think we should go where there is most chance to drill into some frozen ice coming from relatively recent upwelling of deep water veins. To get a reasonable probability these veins should be as close as possble to the surface.</i><br /><br />But ExoMars does not need to find extant life, just where life has been. Hence the importance of sites with abundant clays (Mawrth Vallis, Meridiani Planum, Nilli Fossae) or thick sediments, (Holden and Gale craters).<br /><br /><br /><i>Valles Marineris is a fluvial valley. The lower terrain there might not have been the local lowest point when water was flowing (then may be not the place for a long-lasting sea to form, the water being evacuated Eastwards then Northwards into Vastitas Borealis).</i><br /><br />Vallis Marineris is a very complex and large feature, we should not generalise too much. It is basically a tectonic feature, much modified by mass movement, fluvial, lacustrine and aeolian action. There are thick interior sedimentary deposits and at present the deepest parts are not the outlets.<br /><br /><i>So unless the recent findings of Marsis are for sure linked to water ice (and not ashes), it would seem IMO that the best landing site would be a deep depression like Argyre or Hellas.</i><br /><br />Both Argyre and Hellas are too far south. They are also not specific enough. T <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>
 
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alokmohan

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I am not well acqainted wiyh geography of mars.please specify where to land.
 
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JonClarke

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At the bottom of the BBC link in the original post there is a map showing the locations.<br /><br />You can down load a great Mars map from http://education.usgs.gov/common/resources/mapcatalog/images/planetary/mars_color_topo_11x14.pdf (caution 11.52 MB)<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>
 
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h2ouniverse

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Thanks jon for your analysis.<br />I am in no way expert enough to argue with areologists; It's a good thing that the landing sites considered are all below datum.<br /><br />This being said, I would still have intuitively ranked:<br />1- Hellas basin (Coronae Scopulus)<br />2- Valles Marineris lowest point<br />3- Elysium planitia over "ice" blocks<br /><br />Clays and sediments are fine but with at last a decent bio-lab (not just chemical lab), we should not blow our chance. I am pretty sure that if Exomars finds nothing, other missions will do chemical analysis of various underground anyway, whereas the exobio community will probably be laughed at and won't get another exobio mission for two or three decades. But Exomars for now is unique in its capability to detect extant life. Shouldn't that receive a higher priority than the chemical analysis of clays? (that probably MSL will have performed). This is the first exobio mission since 4 decades!<br /><br />In reply to:<br />------<br />They are also not specific enough. They are too large. Landing sites have to be quite small targets with a wealth of detail. Terby, on the north side of Hellas might just make it. <br />----------<br />1) Exomars rover is not built to do long range exploration as MERs. If we land too far from the target and the target terrain is very specific, we may simply miss it and be out of reach from it(uncertainty at landing+limited mobility). If the desired terrain geology is quite constantly spread over a larger area, the actual landing point will be less important<br />2) Terby is a crater apparently posterior to the Hellas impact. The lowlands in Coronae Scopulus are one of the lowest points on Mars, probably the last refuge of liquid water in Mars history. In addition the terrain there looks relatively young (crater density-wise). And this is not that South (33°S), with a very decent Solar flux on Solar panels. And the undergound in that region should collect all underwater veins of the higher terrai
 
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3488

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Looks as though I have really started something here. <img src="/images/icons/laugh.gif" /><br /><br />Hi Joel,<br /><br />Coronae Scoplus, I have found some things in the links below,<br /><br />Coronae Scopulus 1.<br /><br />Coronae Scopulus 2.<br /><br />Floor of valley within Coronae Scopulus from MRO HiRISE.<br /><br />Hope the above links are of some help?<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>
 
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thereiwas

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Here is an infrared picture of Terby. Interesting melted feature on the northern side. Floor of the crater is at about -5km. (click the 'elevation' button to see false-color heights) This is only 27 degrees south of the equator.
 
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3488

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Hi alokmohan,<br /><br />Landing site selection on any planetary body is a fascinating subject in its own right.<br /><br />There is a story behind every decision.<br /><br />I do not really remember the Viking landers (though I am very familiar with them & the <br />choices behind their landing sites).<br /><br />I do remember Mars Pathfinder & the fact that if Pathfinder landed safely, <br />we would have the first surface images from Mars in 21 years.<br /><br />Ares Vallis where it outflows in Chryse Planitia was the original landing site for Viking 1, based<br />on Mariner 9 orbiter images. When Viking 1 slipped into orbit around Mars, & reimaged that same<br />site, the Ares Vallis site was abandoned for a site to the North West in Chryse Planitia instead.<br />The new Viking 1 orbiter images deemed the Ares Vallis site as being too dangerous.<br />Mars Pathfinder, was sent to Viking 1's original landing site.<br /><br />So it is true, the old saying, what goes around, comes around. <img src="/images/icons/laugh.gif" /><br /><br />When that site was chosen for Mars Pathfinder, one of the retired Viking engineers accused the<br />Pathfinder team, of wrecking their chances, because some 21 years ago, they themselves <br />discarded that site.<br /><br />It was interesting to note, that with airbags, the landing site was not dangerous.<br /><br />It looks as if Viking 1 could have landed there, provided it missed the large boulders, <br />but is probably too dangerous overall for a powered landing IMO.<br /><br />So we did get to see Viking 1's original landing site after all. <img src="/images/icons/laugh.gif" /><br /><br />Viking 2 was to have landed in Cydonia, initially, but once again these images <br />were based on Mariner 9. Cydonia was abandoned due to the site looking too rough & <br />Utopia Planitia was chosen instead (many woo woos<br />claim that Cydonia was rejected <br />because Viking 2 would have shown artificial constructs, total nonsense).<br /><br />With the MERs of <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>
 
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3488

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Hi ThereIWas,<br /><br />Thank you for your link.<br /><br />You might like these also.<br /><br />HiRISE image of layers in Terby Crater.<br /><br />Another HiRISE view of Terby Crater .<br /><br />Article on Terby Crater being a potential Landing Site for the MSL, but could also apply to ExoMars.<br /><br />Layers in Terby Crater MGS-MOC.<br /><br />View of Terby Crater floor from MGS-MOC.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>
 
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h2ouniverse

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Thanks all for the images.<br />Terby looks indeed a very interesting place for a geologist-robot or a chemist-robot. But for an exobio-robot?<br />Are we sure it formed before potential Hellas sea disappeared? <br /><br />To me if we place life detection first, we should account for the following rationale:<br />* organisms if they existed probably thrived first in open water<br />* migrating to underground water pockets or veins means going to less favourable environment: it occurs for most organisms only if forced to<br />* as long as there are seas or lakes, most life will concentrate there<br />* as seas disappear, biotes will progressively concentrate on the lowest points (as well as biotic material)<br />* most organisms will develop underground survival features as the last open water surfaces disappear; so they should develop those evolutionary features WHERE water has last existed in open air, namely at lowest points<br />* given the huge altitude gradient, the underground layer with temperatures warmer than 0°C should be warped (variable altitude), meaning that potential underground layers or veins of water would exert a pressure towards points below low-altitude terrain. In that case, that should favour upwelling from time to time (Artesian wells). Coronoe Scopulus is a very very low point (-8000m) surrounded by terrains above 0.<br /><br />Wouldn't that lead to drill preferentially in lowest point sites?<br />Best regards
 
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h2ouniverse

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Thanks Andrew for the images of Coronae Scopulus lowlands. <br />Do you know whether the surface there is "rover"-able, and whether Marsis has imaged/can image the region radar-wise?
 
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3488

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Hi Joel,<br /><br />AFAIK, there is nothing about MARSIS observations of the canyon in Coronae Scopulus.<br /><br />However, cannot see any reason why not?????<br /><br />Tebry is very interesting, but I suspect it is sterile. A very low elelvation like Coronae Scopulus,<br />IMO may bring some hope, but I do fear, though that Mars is completely lifeless.<br /><br />I hope that I am wrong, but do not hold out any hope.<br /><br />Looking at the first HiRISE image, the canyon floor in Coronae Scopulus, does look very smooth.<br /><br />I cannot access the very highest resolution views as my software does not support it, but with <br />what I have seen, does look rovable. If not, a static Pathfinder type craft, equiped with a bio lab<br />& sampler arm, would do the job.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>
 
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h2ouniverse

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Thank you.<br />I am pretty confident in the possibility for life to be extant in the deep undergound (3000m+). And less optimistic though in the capability for a short-term mission to detect it, as the accessibility will be just... 2 meters!<br />To me the only (dim) hope would be recent upwelling. Frozen bacteria?<br /><br />Regards.
 
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JonClarke

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<i>Clays and sediments are fine but with at last a decent bio-lab (not just chemical lab), we should not blow our chance.</i><br /><br />Remember that ExoMars looks for biosignatures, not life. A very use decision, IMHO, finding life requires us to correctly identify an alien metabolism, Viking showed how difficult that was. Furthermore, life, if present, is going to be rare on the surface and very difficult to target (assuming we know the critical parameters, which we don't). <br /><br />However, past conditions on Mars were much more hospitable and life (if there was any) would have been more widely distributed. Therefore traces of past life - morphological and chemical fossils, biosignatures etc. will also be more widespread. Hence areas with fine-grained sedimentary rocks (clay rich) will be high priority targets. If these areas conatin evidence of present life, then that is a bonus.<br /><br /><i>I am pretty sure that if Exomars finds nothing, other missions will do chemical analysis of various underground anyway, whereas the exobio community will probably be laughed at and won't get another exobio mission for two or three decades. But Exomars for now is unique in its capability to detect extant life. Shouldn't that receive a higher priority than the chemical analysis of clays? (that probably MSL will have performed).</i><br /><br />Remember that Exomars will only drill down 2 m. This is to sample areas protected from weathering, UV, and (perhaps) surface oxidants, rather than look at the subsurface environment. The deep biospheres, if they exist, will be 100's or 1000's of metres down. If ExoMars (and Phoenix and MSL) come up completely negative then this is where attention will turn, but life in any form it will be a long shot by then, I suspect. Drill 100's or 1000's of m is a very tall order for robotic systems, and may have to wait until we have human crews.<br /><br />ExoMars will be characterising the mineralogy with its XRD. This is a must.<br /><br /><i></i> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>
 
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h2ouniverse

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Thanks Jon for your answers.<br />I still get the impression though that Phoenix and MSL are not exobio missions in the true sense, but more chemist robots. Granted, the bio-chip you mention on MSL is a noticeable exception, provided that it has survived the recent descoping of payload.<br /><br />As far as deep biospheres are concerned, I agree with your analysis that prospects are dim to find something close to the surface. Isn't there a possibility however that by artesian mechanisms upwelling may occur from time to time, enabling to get long-lived frozen bacteria / spores from a shallow drilling (as recently discovered in Arctic ices on Earth)? Then wouldn't that favour the selection of low terrain surrounded by high terrain? If Hellas is out of reach(*), wouldn't that place Valles Marineris on top of list? Isn't it then possible to have the clays in Mawrth analyzed by another mission?<br /><br />Regards<br /><br />(*) I can't remember why there is a limit at 10°S... Orbital trajectory?
 
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JonClarke

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<i>I still get the impression though that Phoenix and MSL are not exobio missions in the true sense, but more chemist robots.</i><br /><br />We don't know whether or not there is life on Mars (or anywhere else other than Earth for that matter) so stricly speaking do not have exobiology missions. We can have astrobiology missions that look for signs of life elsewhere.<br /><br />MSL has four science goals, the first one is"Determine whether life ever arose on Mars.".<br /><br />Pheonix has two scientific objectives, the second of which is "Search for Evidence of Habitable Zone and Assess the Biological Potential of the Ice-Soil Boundary." <br /><br />IMHO these mean that both missions have a strong (but not exclusive) astrobiology focus.<br /><br /><i>Granted, the bio-chip you mention on MSL is a noticeable exception, provided that it has survived the recent descoping of payload.</i><br /><br />It did!<br /><br /><i>As far as deep biospheres are concerned, I agree with your analysis that prospects are dim to find something close to the surface. Isn't there a possibility however that by artesian mechanisms upwelling may occur from time to time, enabling to get long-lived frozen bacteria / spores from a shallow drilling (as recently discovered in Arctic ices on Earth)?</i><br /><br />Indeed, which is why some people find artesian springs excellent Mars analogues! <img src="/images/icons/wink.gif" /><br /><br />http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2174.pdf<br /><br />http://www.lpi.usra.edu/meetings/lpsc2003/pdf/1504.pdf<br /><br /><br /><i>Then wouldn't that favour the selection of low terrain surrounded by high terrain? If Hellas is out of reach, wouldn't that place Valles Marineris on top of list?</i><br /><br />Most of the sites mentioned are surrounded by higher terrain and so are potential sites for artesian discharg <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>
 
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gunsandrockets

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<MSL is similarly limited, and may in fact be excluded from the southern hemisphere alltogether.><br /><br />That doesn't sound right, I believe there is at least one location in Hellas which made the list of possible landing sites for MSL. <br />
 
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