the hole in Mars

10kBq Jaro · Senior Member

the hole in Mars

GoogleNaut · Guru

This is pretty darn cool. Thanks for posting it Jaro!

This could be an indication of absolutely vast caverns on Mars--ones big enough to hold oceans of water.

I was attemtping to download the max resolution pix--but the Jpeg is over 400 MB in size!

What an amazing find! Do we cooridinates yet on this thing?

UPDATE:

I have downloaded the 440MB image file, and I have tried installing a freeware viewer called IRFANVIEW which is supposed to handle the JP2000 file format. Trouble is, when you load this gigantic image (or attempt to) into your computer it balloons to 730+ MB and my system blows chunks on it. If any one else wants to try it--the details ought to be staggering!

-- Edited by GoogleNaut at 13:37, 2007-05-27

10kBq Jaro · Senior Member

GoogleNaut wrote:
Do we cooridinates yet on this thing?

The caption says that "The complete image is centered at -5.5 degrees latitude, 241.4 degrees East longitude."

I suspect that most of these lava tube caverns are bone-dry, being situated under the lava plains of the great Martian shield volcanoes, in this case Arsia Mons.
But I suppose that in some rare case, a lava tube cavern may also exist in the higher latitude regions where many water flow gullies have been found in the walls of large meteorite craters.
In that case, an underground lake (liquid or frozen ?) may indeed fill a length of the lava tube.....
I don't recall seeing any photos of lava tubes collapsed for an extended length, showing gullies in the side walls, but I would have to go back and check.... Usually one just sees lots of sand streaming down the sides, with rippled dunes covering the bottom.

But I think that the more important point is that these enormous caverns could be used as ready-made habitats for human colonies, because they could be pressurized with an oxygen atmosphere.
Finding one that also has water (or ice) would of course be a terriffic bonus.

GoogleNaut · Guru

Yeah, Jaro. Thanks for the cooridinates. I wonder if any onf those anomolous methane plumes may originate from this structure or similar ones on the planet...?

I suspect that if life presently exists on Mars, we are going to find it down in one of these holes!

10kBq Jaro · Senior Member

GoogleNaut wrote:
I suspect that if life presently exists on Mars, we are going to find it down in one of these holes!

I just hope its not one of those monster worms, like on the planet Dune wink

.

Andrew · Senior Member

Nah, we would have seen their movement. Those wackers are BIG.

GoogleNaut · Guru

I guess I'd better polish up my "Maker Hooks" if I want to ride the sandworms!

Pretty funny!

I've been thinking about a range of parameters for possible dimensions of the subsurface caverns--and I have cxome to the conclusion that it is possible to give an estimate of minimum sizes based up things like sun incidence angle, and the thickness of the roof 'rind.'

Here is a direct quote from the HiROC website regarding the imaging geometry:

Observation Geometry
Image PSP_003647_1745 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 07-May-2007. The complete image is centered at -5.5 degrees latitude, 241.4 degrees East longitude. The range to the target site was 252.5 km (157.8 miles). At this distance the image scale is 25.3 cm/pixel (with 1 x 1 binning) so objects ~76 cm across are resolved. The image shown here has been map-projected to 25 cm/pixel and north is up. The image was taken at a local Mars time of 03:27 PM and the scene is illuminated from the west with a solar incidence angle of 52 degrees, thus the sun was about 38 degrees above the horizon. At a solar longitude of 233.4 degrees, the season on Mars is Northern Autumn.

Now I am really intruiged--this seems to suggest that the roof 'rind' that we can see may only be a few meters thick, perhaps no more than 10-15 m. This suggests that since diameter of this thing is about 120m, and we see no evidence of illumination of one of the walls, that if the cavern is a vertical shaft illuminated by incident sunlight at 38 degrees is, then the illiminated part of the shaft wall will have a height of: d=(120m)*sin(38) or d=73.9 m vertically. Given the initial diameter of the hole constant incidence angle, this illuminated spot size will also be constant. The position of the spot will move down and back as the wall moves farther away from the hole. For obervation incidence angles nearly vertical (phi=90 degrees or so) then the fact we haven't seen any wall illumination only suggests an overhang--but not what size. To image that illuminated wall spot we will need to reimage the target at a more oblique view, ideally with the satellite's back to the sun so that the observation angle closely matches the illumination angle. If we can image the spot, specifically the bottom edge, then we should be able to narrow the guesses down quite a bit. Two seperate oblique observations should 'triangulate' a solution so that we will have a single set of dimensions that will be very close to dead on.

Of couse, if we could get a pass with the radar instrument we should get a set of reasonably strong echoes indicating the depth to an accuracy of a meter or so. Also, an oblique pass might even give the possibility of a multipath echo which if I remember my optics from physics long ago, I think can tell us something about the 'volume' of the 'resonator' and hence something about the ultimate dimensions of an object being illuminated by radar.

Has anybody had any luck downloading and inspecting the 440 MB maximum resolution image?

-- Edited by GoogleNaut at 17:18, 2007-05-28

10kBq Jaro · Senior Member

GoogleNaut wrote: I've been thinking about a range of parameters for possible dimensions of the subsurface caverns

Ty, here are some interesting links & abstracts....

http://www.norwebster.com/mars/lavatube.html
Martian Lava Tubes Revisited
Presented to the
Second Annual Mars Society Convention
Boulder, Colorado. August 12 - 15, 1999
By R. D. "Gus" Frederick

Disclaimer:
One point to keep in mind during the reading of this paper, is that I am not
trained as a geologist, and that this paper is purely an exercise in
speculation.

Abstract:

One of the key elements for successful long-term human occupation of Mars,
is a viable habitation scheme. Countless ideas have been proposed along
these lines from converted landers to inflatable domes. The advantages of
most schemes thus far are that they are location independent, to an extent.
The lander lands and the habitation is set up. In other words, bring the
habitat to Mars.

But what if ready-made habitats were available? Select locations on the
planet, which with minor modifications, would easily serve as a
semi-permanent base of operations? These locations could well be lava tubes.

Lava tubes are caves formed by flows of highly fluid lava--a "river" of
molten rock flowing from an eruption source, either volcano or fissure.
Often as the flow progresses, the tops and sides solidify. If the flow
source stops, the remaining lava may pour out, leaving a hollow "tube" of
rock. Not all lava flows produce tubes. Sometimes the flow sides form large
"levees" as the sides harden, and the top remains liquid.

On the Earth, the author has personally visited lava tubes on the flanks of
Mount St. Helens, in Washington State, Central Oregon, the Big Island of
Hawaii as well as tubes formed by fissure eruptions in Iceland. Many of the
lava flows identified on the planet Mars feature the same characteristics as
terrestrial flows, including lava tubes and levees. The main difference is a
matter of scale: The Martian features dramatically dwarf their Earth-based counterparts.

This paper offers some speculations on the utilization of these landforms
for the construction of viable human habitats. With examples from many lava
tube-related features here on Earth, I will demonstrate how their much
larger Martian versions could provide a quick, easy and inexpensive way to provide long-term human outposts on the Red Planet.

Snip
==============================================================
http://www.highmars.org/niac/index.html
The Caves of Mars

http://www.highmars.org/niac/niac01.html
About Martian Caves
Dr. Penelope J. Boston; P.I.

Natural subsurface cavities and subsurface constructs present the most
mission effective habitat alternative for future human missions in the
high-radiation environment of Mars. Additionally, lava tubes, other caves,
cavities, and canyon overhangs are sites of intense scientific interest.
They offer easier subsurface access for direct exploration and drilling, and
may provide extractable minerals, gases, and ices. Expanding our NIAC Phase
I feasibility assessment of a subsurface Mars mission architecture for the
scientific exploration and human habitation of caves and subsurface
facilities, we propose a two-part viability demonstration of selected
technologies combined into a functioning system. This system can be
integrated into both robotic precursors and human missions.

Snip

http://www.highmars.org/niac/education/
Educational Projects, Lessons & Resources

The Caves of Mars Project is funded by a NIAC Phase II Grant from the NASA
Institute for Advanced Concepts.
Copyright C 2002-04 - Complex Systems Research; Inc.

-- Edited by 10kBq Jaro at 19:48, 2007-05-28

GoogleNaut · Guru

Thanks for the links, Jaro. This cavern on Mars is really exciting, I have to admit. This is what exploration is all about! I bet we would have a bunch of spelunkers would just love to rappell down into the depths of that thing!

Me, I'd love to use a crane to drop a camera and light package down there first. Put a diode laser/photospectrometer for noncontact chemical compositions; a gas sampler+ gas chromatography analyzer, and a little sample retrieval claw on that thing--and I would be happy as can be!

10kBq Jaro · Senior Member

Here's a nice close-up....

a close-up from the HiRISE instrument onboard the Mars Reconnaissance Orbiter

http://antwrp.gsfc.nasa.gov/apod/ap070928.html

NUKE ROCKY44 · Senior Member

well, well so much for Mars being a one dimensional dusty planet.

There must be geothermal dynamics working within the planet to spew some sort of heat since some of the ice or snow seems to have melted away around
the 4-5 o'clock pattern around the edge of the hole.

Wonder what other crazy stuff Mars exhibits?