So the last day begins with evaluation of the final site: Gale Crater. This site was added back into consideration this summer, driven inpart by new evidence that there is interesting mineralogy in the thick stack of strata inside the crater. The lead talk is presented by Dawn Sumner (using Ken Edgett's slides). An argument is made that Gale represents 'an Early Mars type section'. The landing ellipse itself shares a characteristic with Holden crater, in that you are landing on an alluvial fan. The main advantage of the site is a thick site of strata in the central mound (5000 m of finally bedded materials) -- this thick stratigraphic section has multiple bedding styles and a wide variety of erosional expression.
Along with this thick morphological evidence for stratigraphy, Ralph Milliken describes that Gale has interesting compositional stratigraphy as well -- and there is a lot of connection between thestratigraphy derived from both morphology and composition. There are clays in the lower materials, which the presenters suggest might be lacustrine, and possible sulfate-bearing materials in the upper units. Interestingly, Gale's upper stratigraphy has a yardangy texture of pasted on material, which Ralph compares to ILDs in Valles Marineris (an interesting connection). The final Gale talk is by Brad Thomson, who insists that Gale's stratigraphy can be connected to fluvial activity, and both are in a well understood context and chronology. At this point, the discussion on Gale starts to address possible uncertainty in the lacustrine interpretation of its stratigraphy, and the chronological constraints of this site. Others jump in, but Ken Edgett argues that we don't know much about any stratigraphic sectionon Mars (he says that we know of one lake on Mars, Eberswalde, a second one that's not really that bad ('a distant second') Jezero, and then a whole lot of unknowns).
So following the discussion of the sites, we move on into general discussion. The first major topic is that Jim Bell asks Bethany Ehlmann to really lay out the evidence for the carbonate detection at Nili, because 'he doesn't believe it'. So we are in for some detailed spectral interpretation where I quickly get lost in 'bending-mode this', 'band-depth that', and 'continuum-removal' the other.
The next general discussion topic is that the PIs for the various instruments lay out what they actually think MSL can do, to help incorporate into our votes, and we're off to lunch ... voting will happen first thing after lunch on 11 topics. (see the list here) Tension builds during lunch as various factions try and anticipate how things will go.
Unlike the second workshop, the way voting goes at this meeting is that we have one last round of discussion on each of the sites, and then we vote on paper.
Detailed results are going to be posted at this site, but here is what I could write down:
The top three sites with weighted averages are Eberswalde, Holden, and Gale; all with weighted averages between 40-45. The next two sites are Mawrth and Nili, almost at the same score (~37-38). S. Meridiani finishes sixth, and Miyamoto is much lower than any of the others. We are assured that Mawrth and Nili are not actually dead -- in fact, it is likely that one of them will be brought back into consideration for reasons beyond the scope of this meeting. For example, we know that Holden and Eberswalde are virtually right next to each other, and it is unlikely that both will survive to later stages of consideration. (The old 'actuator' risk that might keep the southern sites from driving still exists, under the radar, but it is still there). We are assured repeatedly that this round of voting is not 'the decision, 'but instead will be factored into the decision carefully. The contingencies that will ultimately result in the next shorter list will be complicated and are beyond the scope of this meeting. Matt Golombek gives us a preview of the next meeting in April; the next workshop will be focused on the 'nitty gritty' of traverses, engineering, and choices about how to actually use MSL to explore the surface.
After the vote is revealed, there is some discussion of whether things were fair: (Diana Blaney: Is there a bimodal distribution related to who is in the room -- basically the 'spectroscopy' sites have sunk to the middle from comparatively favored position at early landing sites...Steve Ruff: Why did the vote go on the questions tailored in this way? A pure ranking would have been better).
So that's that -- *phew*. A bunch of people are bummed out by the results (quite openly), but some are happy (less openly). It'll be interesting to see what landing site actually comes out in the wash next year.
Along with this thick morphological evidence for stratigraphy, Ralph Milliken describes that Gale has interesting compositional stratigraphy as well -- and there is a lot of connection between thestratigraphy derived from both morphology and composition. There are clays in the lower materials, which the presenters suggest might be lacustrine, and possible sulfate-bearing materials in the upper units. Interestingly, Gale's upper stratigraphy has a yardangy texture of pasted on material, which Ralph compares to ILDs in Valles Marineris (an interesting connection). The final Gale talk is by Brad Thomson, who insists that Gale's stratigraphy can be connected to fluvial activity, and both are in a well understood context and chronology. At this point, the discussion on Gale starts to address possible uncertainty in the lacustrine interpretation of its stratigraphy, and the chronological constraints of this site. Others jump in, but Ken Edgett argues that we don't know much about any stratigraphic sectionon Mars (he says that we know of one lake on Mars, Eberswalde, a second one that's not really that bad ('a distant second') Jezero, and then a whole lot of unknowns).
So following the discussion of the sites, we move on into general discussion. The first major topic is that Jim Bell asks Bethany Ehlmann to really lay out the evidence for the carbonate detection at Nili, because 'he doesn't believe it'. So we are in for some detailed spectral interpretation where I quickly get lost in 'bending-mode this', 'band-depth that', and 'continuum-removal' the other.
The next general discussion topic is that the PIs for the various instruments lay out what they actually think MSL can do, to help incorporate into our votes, and we're off to lunch ... voting will happen first thing after lunch on 11 topics. (see the list here) Tension builds during lunch as various factions try and anticipate how things will go.
Unlike the second workshop, the way voting goes at this meeting is that we have one last round of discussion on each of the sites, and then we vote on paper.
Detailed results are going to be posted at this site, but here is what I could write down:
The top three sites with weighted averages are Eberswalde, Holden, and Gale; all with weighted averages between 40-45. The next two sites are Mawrth and Nili, almost at the same score (~37-38). S. Meridiani finishes sixth, and Miyamoto is much lower than any of the others. We are assured that Mawrth and Nili are not actually dead -- in fact, it is likely that one of them will be brought back into consideration for reasons beyond the scope of this meeting. For example, we know that Holden and Eberswalde are virtually right next to each other, and it is unlikely that both will survive to later stages of consideration. (The old 'actuator' risk that might keep the southern sites from driving still exists, under the radar, but it is still there). We are assured repeatedly that this round of voting is not 'the decision, 'but instead will be factored into the decision carefully. The contingencies that will ultimately result in the next shorter list will be complicated and are beyond the scope of this meeting. Matt Golombek gives us a preview of the next meeting in April; the next workshop will be focused on the 'nitty gritty' of traverses, engineering, and choices about how to actually use MSL to explore the surface.
After the vote is revealed, there is some discussion of whether things were fair: (Diana Blaney: Is there a bimodal distribution related to who is in the room -- basically the 'spectroscopy' sites have sunk to the middle from comparatively favored position at early landing sites...Steve Ruff: Why did the vote go on the questions tailored in this way? A pure ranking would have been better).
So that's that -- *phew*. A bunch of people are bummed out by the results (quite openly), but some are happy (less openly). It'll be interesting to see what landing site actually comes out in the wash next year.
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