Dark Cavern Found On Mars

[Radar]

This article has got me thinking.

This hole in the surface of Mars is 100 metres across. It is obviously quite deep because no light is reflected at all. This is quite interesting geology.

http://www.beloblog.com/ProJo_Blogs/shenews/07/marshole.jpg

It can't be an impact zone, it can't be a lava tube either.

Can any theorists here give us an idea of what would have caused this?

:hmm:

[wakaleo]

A worm hole? ;-)

[wakaleo]

A microbe on the lens? Hey Ray, did you notice the smaller one north east of the biggie?

[Radar]

Hi Jim, no I did not see that one. Well spotted. If there is some massive underground chamber down there, you can go in first, I'll stay up top and hold the rope for you. :thumbsupmate:

Ray

[wakaleo]

Whooee! Let's go. We'll have to take your car though. Mine's at the doctor's!

[joe_smith]

They have found about 7 now

http://planetary.org/blog/article/00000984

[Radar]

Hey Joe,

Welcome to the site.

That's pretty cool. Ta for the link.

Where about are you based?

Ray

[joe_smith]

Ingleburn NSW :thumbsupmate:

I would like to know whats below the ground, and how deep they are.

[Radar]

I would like to know whats below the ground, and how deep they are.

That's the million dollar question Joe. I wonder what is below them to. Because there is no flowing water on the surface of Mars, that rules out hydro erosion. The causes of such features are quite elusive at this stage. I'm looking forward to hearing a theory that supports what could have caused these, because currently, I havent got a clue :duh:

Ray

[orion]

I must admit this really has got my attention. Life would have a much better chance to survive in a cave.

[Radar]

Life would have a much better chance to survive in a cave.

It certainly would Ed. Any kind of geothermic action underground can easily support life, just like on Earth. Scientists used to think that all living things needed sunlight to survive, we now know that this is baldadash (which is what I always thought to be honest). Underground creatures that never see sunlight do a process called chemosynthesis. They get energy from different kinds of gases. Mars may no longer be volcanically active, but there would still be vast reserves of gases inside it's core that leak out slowly.

The more we look at Mars, the more interesting it becomes.

Ray

[orion]

Yes Ray, just getting out of the constant radiation bombardment on the surface would be a bonus!

[wakaleo]

Yes, very interesting, especially as most of the holes found are almost perfectly circular. There seems to be a couple of elongated ones just west of north in this photo though - http://hirise.lpl.arizona.edu/PSP_003647_1745.

I've got a few ropes together Ray and pulled my fleecy jumper out of mothballs. Are you ready to go?

[Radar]

More info on this story.

http://space.newscientist.com/article.ns?id=dn12566&feedId=space_rss20

[wakaleo]

I don't know about you Ray, but that latest picture makes it look even more like a hole and not a pit. It seems to me that the vertical walls of the hole have a lower boundary that shows up best in the shadowy section to the bottom right of the picture (http://space.newscientist.com/data/images/ns/cms/dn12566/dn12566-1_771.jpg).

The suggestion that the holes could have been caused from a roof collapse over a lava tube is enticing, but you'd expect the holes to be in a line relevant to the lava flow below them, and that the holes would be elongated in the direction of the lava flow, not circular.

I've seen quite a few lava tubes and their associated roof collapses (only on Earth, of course) but completely different processes could be at work here. For more info on earthly lava tubes, check out these sites:
http://www.undara.com.au/geo/index.html (longest lava flow in the world, despite what the yanks say!)
http://www.goodearthgraphics.com/virtual_tube/virtube.html (interesting virtual lava tube)

Jim

[Radar]

Yeah Jim, I agree. This latest photo just reinforces what was initially thought. The fact NASA have even taken such a detailed image of it shows how interested they are.

Be good if they can time a photo for when the sun is directly above. We'll be able to see much more then.

Ray

[orion]

Be good if they can time a photo for when the sun is directly above. We'll be able to see much more then.

Ray

It depends how deep it is Ray.

One of my all time favorite movies is 'Journey to the Centre of the Earth'. This hole on Mars makes me think about that movie. Who knows maybe now
that they found this hole they might make another Mars SciFi.:hmm:

[Radar]

Yeah would make a good concept for a movie Ed. I've seen that classic movie you mention though, great flick. Those oldies are awesome. With Mars no longer having any kind of volcanic activity, you probably could venture to the centre of it.

Ray

[AstroBob]

long time no see mate. I for one would not be going into that dark hole. good chance of finding water down there though :eek:

[Radar]

G'day buddy. Yeah it's been a while. It would be interesting to pop a camera down and see what lies beneath. I'm sure Mars Global surveyor will be bouncing radar of it soon to figure out what the base consists of. Pretty interesting though.

Ray

[jumpjack]

This argumenti is very intriguing.
I created a web page some months ago, after first image release:
http://lc84.altervista.org/marte/buchi%20marte.html (sorry, only italian...)

I was really "sure" it was a lake. Now I have some doubts; but I didn't deeply examined both images yet.

Anyway, here they are a couple of useful infos for those who like continuing investigations!

First image: http://hirise.lpl.arizona.edu/PSP_003647_1745
Detail: http://hiroc.lpl.arizona.edu/images/2007/details/cut/PSP_3647_1745_cut_b.jpg
Data:
Acquisition date: 5 May 2007
Local Mars time: 3:27 PM
Latitude (centered): -5.5 °
Longitude (East): 241.4 °
Range to target site: 252.5 km (157.8 miles)
Emission angle: 0.6 °
Phase angle: 51.7 °
Solar incidence angle: 52 °, with the Sun about 38 ° above the horizon
Solar longitude: 233.4 °, Northern Autumn



Second image: http://hirise.lpl.arizona.edu/PSP_004847_1745
Detail: http://hirise.lpl.arizona.edu/images/2007/details/cut/PSP_004847_1745_cut_b.jpg
Data:
Acquisition date: 8 August 2007
Local Mars time: 2:34 PM
Latitude (centered): -5.5 °
Longitude (East): 241.4 °
Range to target site: 263.5 km (164.7 miles)
Emission angle: 17.7 °
Phase angle: 25.5 °
Solar incidence angle: 41 °, with the Sun about 49 ° above the horizon
Solar longitude: 292.1 °, Northern Winter

Question1: What are "Emission angle" and "phase angle"?
Question2: Having been shot from different longitudes, could the images be used to create an anaglyph? (Just for the border, of course)

[jumpjack]

By resizing and cutting old and new images, I obtained two "overlappable" images, which allow easy comparisons:
old image (http://www.planetmobile.it/jumpjack/immagini/mars-lake-1.jpg) (just cut)
new image (http://www.planetmobile.it/jumpjack/immagini/mars-lake-2-edit.jpg) (cut and rotated)

Are we looking at a TUNNEL??? Going down in the ground while going to the left?!?

edit: fixed image links

[jumpjack]

First image data:
GROUP = VIEWING_PARAMETERS
INCIDENCE_ANGLE = 52.334825 <DEG>
EMISSION_ANGLE = 0.626095 <DEG>
PHASE_ANGLE = 51.723667 <DEG>
LOCAL_TIME = 15.45518 <LOCALDAY/24>
SOLAR_LONGITUDE = 233.400806 <DEG>
SUB_SOLAR_AZIMUTH = 158.979396 <DEG>
NORTH_AZIMUTH = 270.000000 <DEG>
END_GROUP = VIEWING_PARAMETERS

Second image data:
GROUP = VIEWING_PARAMETERS
INCIDENCE_ANGLE = 41.168794 <DEG>
EMISSION_ANGLE = 17.705339 <DEG>
PHASE_ANGLE = 25.519371 <DEG>
LOCAL_TIME = 14.57412 <LOCALDAY/24>
SOLAR_LONGITUDE = 292.105117 <DEG>
SUB_SOLAR_AZIMUTH = 150.615206 <DEG>
NORTH_AZIMUTH = 270.000002 <DEG>
END_GROUP = VIEWING_PARAMETERS


How should I use these data???
How can I plot a line on the image, to show the sun direction?

[jumpjack]

First image data:
How should I use these data???
How can I plot a line on the image, to show the sun direction?
ah, ok:
http://isis.astrogeology.usgs.gov/Application/presentation/Tabbed/mdisedrinfo/mdisedrinfo.html

Ok, sorry, I'll stop posting till further reading/studyng the images :)

[jumpjack]

SO, here it is the result of my study on new image:
http://www.planetmobile.it/jumpjack/immagini/lago-marte-new.JPG

Original image for comparison:
http://hirise.lpl.arizona.edu/images/2007/details/cut/PSP_004847_1745_cut_b.jpg

http://www.planetmobile.it/jumpjack/immagini/angoli.JPG
It really looks like a tunnel! Or, anyway, a very deep crater with very steep borders!

[timthelder]

great pic's there jumpin jack,

That baby's about 160m across,you can easily fit two Boeing 747's in there.

I haven't read any of the scientific theories yet,but looks like due to the over-hang in the lower right of the pic it would almost have to have been created by the falling away of the soil? from underneath.Also all the way around the circumference there is a slight sloping of the edge.

My OP,I think there is probably a VERY large cavern several meters down left over from past volcanic activity.To cause the hole,a meteor(much smaller than the actual hole size)impacted the surface causing an immediate collapse.That is why there is no crater(it fell in with the soil at the time of impact.)Also I would say it's been there a very long time due to the small impact craters in the side of the hole.

Basis for my theory is this...I live in what is called a karst region(caves and sinkholes everywhere)ofcourse the caverns in this area where created by water.

In town,there was a collapse in two seperate places underneath roadways.This isn't a regular occurrence but it has happened twice.The same effect could be created if say you dropped a 60 ton ball on the ground above a cavern or cave system.In one of our industrial areas,they actually do this to cause any caves to collapse before they begin developing the property.

Another reason I think this is because as a young lad,there was a one meter hole on the back of my grandpa's farm.It opened up into a large elongated cavern.You had to be let down into it with a rope.

Same scenario,just a bigger hole,and a MUCH bigger cavern.

It still gives me goosebumps though...

[AstroBob]

Interesting pics Jumpjack. I didn't realise the hole was so big.

[jumpjack]

My new page about new image is ready. ;-)
http://lc84.altervista.org/marte/buchi-marte-2.html

Over 140 meters deep! (against 160m width)

[Radar]

Awesome mate. 140 metres deep. That new webpage looks good.

:thumbsupmate:

[wakaleo]

Gidday Jumpjack

Hmm, your calculations on this hole make it even more intriguing. Well done.

Jim

[Mick]

Awesome stuff, the posted image is on APOD today.

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

[AstroBob]

I missed this but saw it on the news. shame nasa doesn't have some kind of email alert reminder.

[jumpjack]

How can I know the direction from which the sun light comes in this photo?

http://lc84.altervista.org/marte/immagini/mars-lake-2-edit.jpg

The PDS label (http://hirise-pds.lpl.arizona.edu/PDS/RDR/PSP/ORB_004800_004899/PSP_004847_1745/PSP_004847_1745_RED.LBL)only specifies vertical angle: what about the horizontal one?!? Does the light come from left, right, down, downleft...?

And how can I know the spacecraft longitude with respect to the crater? Was it to the left or to the right of it while taking the picture?



All of these data are needed to properly estimate hole's data (dept, slope,...)



Any help?

[jumpjack]

I found full data about "mars holes" images; this is an excerpt of the 50 MB file (which refers to dozens of images):
http://www.planetmobile.it/jumpjack/buchi-marte-dati-completi.txt

But I am not yet able to determine exact sunlight direction, I obtain strange longitude values, which look no matching with "local time" valule: being the time past 12.00 PM, sun should be to the right of the hole... so, how can solar longitude be 189.57, being center image latitude 241.3980??? :duh: Shouldn't it be >241.3980?!?

(Fields list (http://hirise-pds.lpl.arizona.edu/PDS/INDEX/EDRINDEX.LBL)) (original file (http://hirise-pds.lpl.arizona.edu/PDS/INDEX/EDRCUMINDEX.TAB) WARNING!! 50 MB!!)

[jumpjack]

An update in hirise pages format now reveals which is the exact sun direction
My last calculation reveals that the hole should be at least 254 meters dept! :duh:

http://www.planetmobile.it/jumpjack/immagini/prof.GIF

[wakaleo]

An update in hirise pages format now reveals which is the exact sun direction
My last calculation reveals that the hole should be at least 254 meters dept! :duh:

http://www.planetmobile.it/jumpjack/immagini/prof.GIF

Do you mean the depth of the hole or the apparent height of the walls, Jumpjack?

Jim