Abstracts to 2007 Lunar and Planetary Science Conference are up.

[exoscientist]

2007 Lunar and Planetary Conference.<br />http://www.lpi.usra.edu/meetings/lpsc2007/<br /><br /><br /> Bob Clark <div class="Discussion_UserSignature"> </div>

 

[JonClarke]

TITAN<br /><br />Lakes<br /><br />http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2322.pdf<br /><br />http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2081.pdf<br /><br />Channels <br /><br />http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2028.pdf<br /><br />Dunes<br /><br />http://www.lpi.usra.edu/meetings/lpsc2007/pdf/1412.pdf<br /><br />MARS<br /><br />Alaskan icy debris flows as analogues for Martian gullies<br /><br />http://www.lpi.usra.edu/meetings/lpsc2007/pdf/1813.pdf <br /><br />Dry valley gullies in Antarctica as Mars analogues<br /><br />http://www.lpi.usra.edu/meetings/lpsc2007/pdf/1617.pdf<br /><br />http://www.lpi.usra.edu/meetings/lpsc2007/pdf/1656.pdf<br /><br />http://www.lpi.usra.edu/meetings/lpsc2007/pdf/1678.pdf<br /><br /><br />FUTURE MISSIONS<br /><br />Orion missions to NEOs<br /><br />http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2292.pdf<br /><br />http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2083.pdf<br /><br />VENUS<br /><br />ESA Venus entry probe<br /><br />http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2386.pdf<br /><br /> <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>

 

[JonClarke]

I am glad you found the abstract about the Antarctic slope streaks, I found it most challenging and interesting but then couldn't find it again, which is why it was not in my list. I am going to have to re think my opinions about the streaks being dry flow phenomena, for sure.<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>

 

[exoscientist]

Thanks for that link to the report on the dark streaks in Antarctica, Borman.<br />The dark streaks on Mars became famous because they are widespread features that are seen to be being currently generated on Mars. <br />The prevailing view has been they are dry dust flows. However, the report to be presented to the 2007 Lunar and Planetary Science conference notes that closely analogous features occur in Antarctica and the authors of the report note the Antactica streaks are due to freeze-thaw cycles:<br /><br />SLOPE STREAKS IN THE ANTARCTIC DRY VALLEYS: CHARACTERISTICS, CANDIDATE FORMATION MECHANISMS, AND IMPLICATIONS FOR SLOPE STREAK FORMATION IN THE MARTIAN ENVIRONMENT. <br />J. W. Head1, D. R. Marchant2, J. L. Dickson1, J. S. Levy1 and G. A. Morgan1. <br />1Dept. Geol. Sci., Brown Univ., Providence, RI 02912 USA (****@brown.edu), 2Dept. Earth Sci., Boston University, Boston MA 02215 USA (****@bu.edu). <br />Lunar and Planetary Science XXXVIII (2007) 1935.pdf <br />http://www.lpi.usra.edu/meetings/lpsc2007/pdf/1935.pdf<br /><br />This is important because the dark streaks are wide spread near the equator <br />on Mars. If is true that they are due to freeze-thaw cycling as they are in <br />Antarctica that would mean that freeze-thaw cycling and therefore liquid water is widespread near the equator on Mars. <br />I had earier noted in the post to sci.astro copied below that streaks seen on slopes in Antarctica are similar to the Mars streaks. I surmised the formation of the streaks in Antarctica were due to freeze-thaw cycles. <br />Since debris flows on slopes in general occur in periglacial regions other than Antarctica due to freeze-thaw cycling there may also be dark streaks as well in such regions, in Europe or North America for example:<br /><br />Scree slopes. <br />http://www.tiscali.co.uk/re <div class="Discussion_UserSignature"> </div>

 

[exoscientist]

Here's an image of the slope streaks in Antarctica from the 2007 LPSC report. Notice the similarity to the Mars dark streaks, including the digitate ends (finger like.)<br /><br /> Bob Clark <div class="Discussion_UserSignature"> </div>

 

[yevaud]

Unless I am very much mistaken, here's an abstract being presented, with out own Jon Clarke as co-author:<br /><br />http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2111.pdf <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[exoscientist]

<blockquote><font class="small">In reply to:</font><hr /><p>Collapse pits or geyser spouts? <br /><br />In the May 23, 2007 release, Gullies and Dunes in a Crater in Newton Basin, http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_003464_1380 <br /><br />There appear some interesting circular depression features near apron incisions. The features seem too small to be associated with a sub surface fracture such as a catena and they also appear further upslope. <br /><br />Two possible ideas come from recent 2007 LPSC abstracts. One is: GULLIES POTENTIALLY FORMED BY WATER FROM THE SUBSURFACE. <br />By Kolb et al <br />http://www.lpi.usra.edu/meetings/lpsc2007/pdf/1391.pdf <br /><br />Here noted depressions, though not circular may be due to sapping of subsurface water to form gullies. Water moves and washes out some subsurface dust and the surface collapses. <br /><br />Another idea consistent with the circular nature could be due to eutectic melting due to some salt such as CaCl2 landing upon the surface and causing any ice mixed within the dust to melt. <br />IMPACTS, SALTS, AND ICE ON MARS: HOW BRINE FLOW IN YOUNG GULLIES AND ELSEWHERE COULD BE RELATED TO IMPACT CRATERING. <br />By Burt and Knauth <br />http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2054.pdf <br /><br />Here either erosion or inverted impact gardening delivers salt to the locale where, like road salt, pockets of melting commence. <br />...<br /><p><hr /></p></p></blockquote><br /><br /> I noted that in the MOC image of the gullies of Newton crater there was a great deal of low lying fog or haze in the image:<br /><br />Evidence for Recent Liquid Water on Mars:<br />Channeled Aprons in a Small Crater within Newton Crater<br />MGS MOC Release No. MOC2-242, 22 June 2 <div class="Discussion_UserSignature"> </div>

 

[exoscientist]

Borman, everyone with an interest in Mars should be familiar with the temperature maps shown here: <br /><br />South Polar Cap Recession. <br />http://www.mars-ice.org/sp99.php <br /><br /> They show that TES measurements indicate that the temperatures on Mars can reach 0 degrees C even as far south as 70S latitude.<br /><br /> The pole facing nature of these gullies is consistent with the most recent analyses that show in the latitude range of 30S to 45S gulllies are predominantly pole facing. In addition to the Heldemann/Mellon reference you cited that shows this, here's another paper that reaches the same conclusion:<br /><br />Martian gullies in the southern mid-latitudes of Mars: Evidence for climate-controlled formation of young fluvial features based upon local and global topography.<br />Icarus, Volume 188, Issue 2, p. 315-323.<br />http://www.planetary.brown.edu/pdfs/3138.pdf<br /><br /> I did see the roundish features in the image you mentioned, but could you point out where the gullies cross-cut them?<br /> The pole facing orientation of the gullies could be explained by a deposition origin by assuming this allows the snow/ice to collect on the walls.<br /> But I seem to recall there was an argument for how subsurface water could be released from pole-facing slopes.<br /><br /><br /><br /> Bob Clark <div class="Discussion_UserSignature"> </div>

 

[exoscientist]

Some Hirise images in the vicinity of the MOC image by searching under the latitude/longitude range -45 to -35 lat and 190 E to 210 E long:<br /><br />HiRISE | Latitude/Longitude Search Results.<br />http://hirise.lpl.arizona.edu/geographikos.php?q1=-45&q2=-35&q3=190&q4=210&order=release_date&submit=Search<br /><br /> One of these has the intriguing title:<br /><br />HiRISE | Location of Possible Very Recent Gully Activity (PSP_002040_1435).<br />http://hirise.lpl.arizona.edu/PSP_002040_1435<br /><br /><br /><br /> Bob Clark <div class="Discussion_UserSignature"> </div>

 

[exoscientist]

Borman, I found this abstract on a Mars conference site that might explain the round depressions you noted:<br /><br />Evidence for widespread and recent (very late Amazonian) ponding in Utopia and western Elysium Planitia, based on terrestrial polar analogues.<br />Osinski G. R. (1) and Soare R. J. (2,3)<br />(1) Canadian Space Agency, 6767 Route de l’Aeroport, Saint-Hubert, QC J3Y 8Y9, Canada (****@space.gc.ca), (2) Department of Geography, Planning and Environment, Concordia University, 1355 de Maisonneuve W., Montreal, H3A 1M8 QC, Canada, (3) Department of Geography, Dawson College, 3040 Sherbrooke St. W., Montreal, H3Z 1A4 QC, (****@dawsoncollege.qc.ca)<br />On Earth, thermokarst ponds occur in ice-rich regolith whose thermal equilibrium has been disturbed. Using Hi-Rise, MOC and THEMIS images, we have identified scalloped depressions in Utopia and western Elysium Planitia that are consistent in scale and morphology with drained thermokarst ponds (alases), present in the Canadian Arctic. Pingo-like mounds and thermal contraction (possibly ice-wedge) polygons also are widespread in the region. By analogy with terrestrial polar regions, this suggests that periglacial processes could have played an important role in the development of the regional landscape on Mars. We focus on the possible alases and show that two of their characteristics – internal terraces and small orthogonal polygons – are uniquely consistent with ponded water and then water loss by episodic evaporation or slow drainage. The characteristics are not consistent with water loss by sublimation. In terms of age, the alas-like features could be very young. In some instances, they cross-cut gullies and are superposed on them. As the gullies themselves are thought to be amongst the youngest geological features on Mars, this points to the depressions being younger still. We propose that the scalloped depressions are youthful features whose evolution is a product of very recent shifts in obliquity, w <div class="Discussion_UserSignature"> </div>

 

[exoscientist]

By checking the Hirise images in the link with images in the same vicinity, it's clear that the fog/haze is a common occurrence in this region. <br /> Low lying fogs composed of water/ice are not uncommon on Mars as indicated in this image of the western end of Valles Marineris:<br /><br />http://img.villagephotos.com/p/2005-4/986073/marsiswet.jpg<br /><br />taken from:<br /><br />Adsorption water-driven processes on Mars.<br />D. Möhlmann, DLR-PF, Berlin.<br />FIRST MARS EXPRESS SCIENCE CONFERENCE. 21-25 February 2005, ESA/ESTEC<br />http://sci.esa.int/science-e/www/object/doc.cfm?fobjectid=36779<br /><br /><br /> Bob Clark <div class="Discussion_UserSignature"> </div>

 

[exoscientist]

<blockquote><font class="small">In reply to:</font><hr /><p>Valles Marineris is not at 41 degress south latitude. <p><hr /></p></p></blockquote><br /><br />Yes, but it is an important point that needs to be remembered that maximum temperatures even this far south can be above the melting point. For instance according to the graph showing TES temperature readings the max temperature can exceed 20 C at 45 S latitude.<br /><br /><br /> Bob Clark <div class="Discussion_UserSignature"> </div>

 

[3488]

Thanks all,<br /><br />I would love to attend one of these meetings.<br /><br />Hi Jon & Bob, I hope that you will not object to me downloading these documents<br />& charts?<br /><br />I am & have learned an awful lot from you two. Thank you very much indeed.<br /><br />Fascinating stuff, thank you all very much.<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>

 

[exoscientist]

Here's a Hirise image of the Newton crater that pretty clearly shows low lying fogs:<br /><br />HiRISE | Crater and Gullies in the Newton Basin (PSP_002119_1380)<br />http://hirise.lpl.arizona.edu/PSP_002119_1380<br /><br /> Here's the browse image:<br /><br />http://hirise-pds.lpl.arizona.edu/PDS/EXTRAS/RDR/PSP/ORB_002100_002199/PSP_002119_1380/PSP_002119_1380_RED.browse.jpg<br /><br /><br /> Bob Clark <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

When I read your post fast the first time, I thought it said low lying frogs <img src="/images/icons/laugh.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[exoscientist]

The graph of temperatures in the southern hemisphere I gave shows even at this time of the year the surface temperature can be above -50 C at this latitude. Depending on how far above the surface the fogs are this could correspond to water ice fogs.<br /> Also, this Hirise image from the same general vicinity and also during southern winter shows frost that is described as water ice since the temperatures are too high for CO2 to condense (at least on the surface):<br /><br />HiRISE | Frost Covered Gullies (PSP_001552_1410).<br />http://hirise.lpl.arizona.edu/PSP_001552_1410<br /><br /> Such dense low lying fogs could be the source of this frost.<br /><br /><br /> Bob Clark<br /> <div class="Discussion_UserSignature"> </div>

 

[exoscientist]

The pages are indeed confusing about when the images were taken. The acquisition time for both of them is given as January 1, 2007. <br /> However, a clue that this can not be correct is indicated by the orbit numbers for the images. The orbit numbers are part of the catalog numbers for the images. One was taken during orbit 2119 and the other during orbit 2330. MRO orbits take about 2 hours so they were actually taken more than 400 hours apart.<br /> This is confirmed by reading the info on the "Full PDS label information" link for each image. For the image with the fogs, the info given for the time is:<br /><br />/* Time when the observation first started */<br />MRO:OBSERVATION_START_TIME = 2007-01-08T13:19:11.895<br /><br /> For the later image you cited it's:<br /><br />/* Time when the observation first started */<br />MRO:OBSERVATION_START_TIME = 2007-01-24T23:54:54.532<br /><br /> As for why the "Local Mars time" for the images is so close, I believe Mars orbital spacecraft are often given polar orbits that make the local time they appear over the same location at different orbits be approximately the same.<br /> <br /><br /> Bob Clark <div class="Discussion_UserSignature"> </div>