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View Full Version : What will Mars Reconnaissance Orbiter find?



RGClark
2006-Apr-06, 06:52 PM
With each factor of 10 improvement of visual resolution of Mars has
come revolutionary changes in our understanding of the role of liquid
water on Mars. What revolutionary improvement over the discovery of
possibly currently forming gullies by MGS might we predict for MRO?
I suggest small ponds will be observed by MRO on Mars, oases if you
will. These will be analogous to Don Juan pond in Antarctica. Note that
Don Juan pond is able to remain unfrozen year round down to perhaps -45 C
temperatures because of abundant salts. The MER rovers suggest such
salts are also abundant on Mars.
I believe that such ponds have been seen by MGS, but they have been
hard to prove at the resolution of MGS. I'm suggesting they will be
proven by MRO. Note that the Malin-Edgett gullies were not discovered
by Viking orbiter imaging, but the fact that THEMIS on Mars Odyssey has
been able to detect them at similar resolution to the Viking orbiter
resolution suggests they were visible by Viking, just not provably so.

A *possible* example of ponding seen by MGS:

Mars Orbiter Camera (MOC) High Resolution Images:
Seepage and Ponding within a Southern Hemisphere Crater
http://www.msss.com/mars_images/moc/5_27_98_agu_release/

My guess for where they will be found is at near equatorial areas that
are known to have low lying fogs or clouds:

Clouds in Noctis Labyrinthis on Mars.
http://www.photovault.com/Link/Universe/Planets/Mars/UPMVolume01/UPMV01P02_06NoctisLabyr.html

Note that the frost deposition on the MER Opportunity rover was
observed in connection with clouds over the site. The fogs/clouds seen
over Noctis Labyrinthis are much denser and closer to the surface.
Indeed they look more like cumulus clouds than thin cirrus clouds,
which is why I'm suggesting visible surface ponds with better
resolution imaging. To be precise, I'm predicting such ponds will be
seen during the period such low, dense fogs are seen over these near
equatorial locations.

Here is another image of the western end of Valles Marineris showing
dense low lying fogs/clouds:

http://img.villagephotos.com/p/2005-4/986073/marsiswet.jpg

taken from:

Adsorption water-driven processes on Mars.
D. Möhlmann, DLR-PF, Berlin.
FIRST MARS EXPRESS SCIENCE CONFERENCE. 21-25 February 2005, ESA/ESTEC
http://sci.esa.int/science-e/www/object/doc.cfm?fobjectid=36779

Another possible location for ponding is in Newton crater:

Evidence for Recent Liquid Water on Mars:
Channeled Aprons in a Small Crater within Newton Crater.
http://www.msss.com/mars_images/moc/june2000/newton/

At 41 S latitude, this is not a near equatorial site, but there are
abundant low lying fogs in the image and the connection with gullies is
suggestive.

Another possible site may be the Hellas crater basin since this also
presents frequent low lying fogs or clouds.

Some MGS images of Hellas are here:

MOC Narrow-Angle Image Gallery: Mars Chart 28: Hellas
http://www.msss.com/moc_gallery/m07_m12/mc28.html


Bob Clark

RGClark
2006-Apr-08, 11:22 PM
Jeffrey Kargel who is a leading expert on Mars glaciology discusses the possibility of current liquid water brines on Mars here:

MARS AS A SALT-, ACID-, AND GAS-HYDRATE WORLD.
J.S. Kargel and Giles M. Marion, USGS Astrogeology (2255 N. Gemini Dr., Flagstaff, AZ 86001, ****@usgs.gov), Desert Research Inst. (Reno, NV)
Lunar and Planetary Science XXXV (2004) 1965.pdf
http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1965.pdf


Bob Clark

RGClark
2006-Apr-08, 11:28 PM
This report calculates that .2% of the water at the surface could be unfrozen as a liquid water brine:

UNFROZEN GROUNDWATER IN THE MARTIAN CRYOSPHERE.
R.E. Grimm, M. Bullock, S.Dec, S. Jepsen, G. Olhoeft, S. Painter, J. Priscu; Dept. of Space Studies, Southwest Research Institute, 1050 Walnut St. #400, Boulder CO 80302 (****@boulder.swri.eduUNFROZEN edu); Dept. of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO; Dept. of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT; Dept. of Geophysics, Colorado School of Mines, Golden, CO; Center for Nuclear Waste Regulatory Analy-sis, Southwest Research Institute, San Antonio, TX.
Lunar and Planetary Science XXXVII (2006) 2090.pdf
"Introduction: Unfrozen water is present as thin films surrounding soil or rock surfaces at subfreezing temperatures. On Mars, this unfrozen water will affect geochemistry and could provide microbial habitats. Unfrozen water may persist kilometers above the base of the cryosphere, or perhaps even transiently at the surface."
...
"The thermodynamic theory of unfrozen soil water [10-11] relates the soil-freezing characteristic curve (temperature vs. unfrozen water content) to the soil-moisture characteristic curve (capillary pressure vs. water content). In this way, parameters derived from the study of unsaturated soils [12] can be used to predict unfrozen water content. Such calculations can greatly extend the predictive range for Mars over em-pirical fits, particularly the effect of freezing-point depression due to briny groundwater."
http://www.lpi.usra.edu/meetings/lpsc2006/pdf/2090.pdf



Bob Clark

loglo
2006-Apr-09, 02:45 AM
Bob,

Thanks for the links, haven't seen many of these pictures before.

I'm hoping they'll be able to find a source for the methane that has been detected. If its a volcanic warmspot it would be a major find since almost nothing is known of the sub-regolith processes.

I'd also like to see if they can start to discriminate between water formed runoff features and the other possibilities that have been suggested, dust, CO2 etc. Then we will be able to pin down the geological history a lot tighter.

I also read recently (http://www.space.com/scienceastronomy/051019_crater_count.html) that the rate of cratering may have to be revised as many are probably from secondary impacts. Given the detail of crater floors that is shown in the first MRO pictures it should be able to characterise these a lot better too.

All in all its going to be a fun-filled few years. :)

novaderrik
2006-Apr-09, 08:37 AM
i wonder what the new higher res pics of certain "ruins" will reveal. much like the new view of the "face" showed it to be just another well weathered hill, i wonder what all those "pyramids" and "statues" will turn out to be..

antoniseb
2006-Apr-09, 12:47 PM
I'll be interested in seeing the tracks that the MER rovers left. Not because we'll see something new, but because it will help me to understand the level of detail that it can image, and more importantly, it will let me see what it can't see, as the MER's have some very detailed images taken along the way.

Launch window
2006-Apr-11, 07:27 AM
It will find many, many things,
each spacecraft in the past years has done some amazing work such as Mars Reconnaissance Orbiter, the Russian Phobos mission, ESA's Mars Express, the United States Mars Odyssey. With each new mission a new level of detail on Mars is returned.

MRO clearly is the next generation craft, more advanced than the rest and the results will be amazing

However I think a time will come where we have to stop sending robotic orbiters because there is only so much science they can give us and therefore we will need to move onto a bigger project Human precursor missions or Sample-returns

antoniseb
2006-Apr-11, 12:43 PM
I think a time will come where we have to stop sending robotic orbiters because there is only so much science they can give us and therefore we will need to move onto a bigger project Human precursor missions or Sample-returns

Sample return will be nice, though I think that we will also be sending some robotic factory missions long before we send people. Likewise for the moon (though in the case of the moon, we may have some limited number of manned missions before the robotic factories).

Launch window
2006-Apr-12, 11:09 AM
Sample return will be nice, though I think that we will also be sending some robotic factory missions long before we send people. Likewise for the moon (though in the case of the moon, we may have some limited number of manned missions before the robotic factories).

This is why I was upset to see so many unmanned craft cut back so suddenly, the robotic landers and such are badly needed if we are going to continue with this 'VSE'

RGClark
2006-Apr-15, 08:07 PM
According to this news release, MRO comes to within 100 km of the Martian surface at closest approach during aerobraking:

Mars cameras debut as NASA craft adjusts orbit
MISSION STATUS REPORT
Posted: April 13, 2006
"The orbiter is currently flying in very elongated loops around Mars. Each circuit lasts about 35 hours and takes the spacecraft about 27,000 miles (43,000 kilometers) away from the planet before swinging back in close.
"On Wednesday, a short burn of intermediate sized thrusters while the orbiter was at the most distant point nudged the spacecraft to pass from approximately 70 miles (112 kilometers) to within 66 miles (107 kilometers) of Mars' surface."
http://www.spaceflightnow.com/news/n0604/14mro/

At its final orbit it will be about 300 km above the surface. At that distance the high resolution camera HIRISE is expected to have a resolution of 0.28 meters per pixel.
But at the 100 km distance the resolution would be 1/3 this - 3.6 INCHES PER PIXEL(!)
Can MRO take high resolution imaging at closest approach during aerobraking?


Bob Clark

antoniseb
2006-Apr-15, 08:32 PM
at the 100 km distance the resolution would be 1/3 this - 3.6 INCHES PER PIXEL(!)
Can MRO take high resolution imaging at closest approach during aerobraking?

My guess would be that it would endanger the camera and result in images blurred by the buffeting the craft will experience during aerobraking.

RGClark
2006-Apr-16, 04:01 PM
My guess would be that it would endanger the camera and result in images blurred by the buffeting the craft will experience during aerobraking.

At least for protecting the camera, it can be pointed away from the direction of motion.
I don't know what the effects of the residual atmosphere on the stability of the scan platform at that altitude would be.


Bob Clark

ToSeek
2006-Apr-20, 03:14 PM
From what I've read there are no plans to do imaging (at least not with the fancy camera) during aerobraking.

Romanus
2006-Apr-20, 11:09 PM
Guessing what our probes will find has almost always been a failed bet; I'm willing to believe that MRO will find things we have yet to postulate. :)