High Cliffs Surrounding Echus Chasma on Mars (23 Jul 2008)

[henk21cm]

Concerns http://antwrp.gsfc.nasa.gov/apod/ap080723.html

Look at the section in the center line of the image, at the left side. The cliffs extending from the higher plateau to the bottom. At the edge there are linear structures, like the grains in a file.

On a much smaller scale i saw similar structures when:

• Water runs over a large heap/mound of sand. Initially due to erosion water cuts a narrow and shallow pattern in the sand, just a few grains of sand. Since such a 'channel' is deeper than the rest, it 'contracts' more water and subsequently the patterns are deepened.
• On a large heap/mound of very dry sand, the local stability of a group of sand grains is compromised. Some sand 'rains' down along the slope, carving similar patterns.

Although not mentioned in the caption of the image, nor at the website of the Mars Express, i suppose that the colours are not the actual colours. Mars would have been known as 'the blue planet'.

[neufer]

Concerns http://antwrp.gsfc.nasa.gov/apod/ap080723.html
Although not mentioned in the caption of the image, nor at the website of the Mars Express, i suppose that the colours are not the actual colours. Mars would have been known as 'the blue planet'.

'The blue planet' is already taken, thank you very much.
http://earthobservatory.nasa.gov/Newsro ... t_h264.mov

The blue is no doubt enhanced compared to the red
but the two major (non-ice) colors of Mars are:

1) orange/red (for rust) and
2) purple/blue (for 'blueberries').

http://antwrp.gsfc.nasa.gov/apod/ap080714.html

[emc]

You may be right about the false color Henk, but we usually get some mention of this in the text or resource site... my first impression was false color because of the stark contrast I haven't seen on other Mars (normal) images.

I was captured by the great cliff of course, but my eye drifted to the upper right quadrant and was intrigued by what appears to be a circle in the sand... I let my imagination take over and discovered a surfacing Mars sand whale... my imagination carries me away sometimes.

[orin stepanek]

It looks like there may have been a crater below the large one that got wiped out. Do you suppose that there may have been some plate tectonics going on at one time? That could account for severe lava flow.
I was wondering what the dark color was. Seems like it would be an awfully lot of blueberries.

Orin

[emc]

Hmmmm... rusty blueberries for breakfast... must be a favorite of Mars sand whales???

[henk21cm]

G'day Ed,

You may be right about the false color Henk, but we usually get some mention of this in the text or resource site... my first impression was false color because of the stark contrast I haven't seen on other Mars (normal) images.

went for the hirise website and found 6 images related to the Echus Chasma. None of them show similar dark colouration as the plateau in todays APOD.
Next i downloaded the big image and toyed around with the colour planes. Changed red into blue and blue into red. Rotated the colours of the colour planes. Permutated the colours of the colour planes. None of these actions produced a colour similar to the colours found by the Rovers and by Phoenix. (BTW, its very quite on the Phoenix front. A lot of scraping, however it never found your pony nor any baleen)

Took the original blue colour plane, promoted it to the red colour plane with full intensity, left out the entire blue colour plane, used half the intensity of the original blue colour plane for the green colour plane. Still no good. In stead of half, used one quarter. No good. Subtracted 30 from the intensity of green and 50 from blue: no good.

The weirdest and most recognizible image i got is when:
red = original green
green = original blue
blue = original red
A striking resemblance with the white cliffs of Dover(UK), with their green pastures on top.

[bystander]

I was captured by the great cliff of course, but my eye drifted to the upper right quadrant and was intrigued by what appears to be a circle in the sand... I let my imagination take over and discovered a surfacing Mars sand whale... my imagination carries me away sometimes.

I see several. Two larger ones, and some smaller ones.

"Sand whales"? How about sand worms? May be spice deposits.

[apodman]

According to http://www.space.com/scienceastronomy/h ... 40319.html ...

"blueberries" ... are, for the record, gray in color

---

Nice depth in today's APOD for just a 2D view.

[emc]

Thanks for the links guys, I found this at ESA... more images of Echus Chasma... not quite a dramatic as today's APOD though. IMHO

[emc]

"Sand whales"? How about sand worms? May be spice deposits.

I always thought Mars would make a good setting for Dune.

http://asterisk.apod.com/vie ... es+thawing (scroll down to neufer's post)

[Arramon]

Yesss.... the spice must flow....

[Bad Buoys]

Since most APODs are color filtered/enhanced I've long ago stopped giving any relevance to blueberries. But this APOD is stunning!

Without any analysis it looks so Earthly. The huge, slumped plug from the crater forward to the "bay" seems to be a "slide" which here on the banks of the Columbia, would be caused by either water saturation, base erosion or an earthquake. Any could be the case here on Mars, with the later suggesting plate tectonics.

And what of the smooth valley floor in the foreground? What if this is water[ice]? The shore sure looks like a large frost wave. Water might be very prevalent on Mars, just in a solid, soil covered form. But it looks quite accessable, especially at the poles.

[iamlucky13]

(BTW, its very quite on the Phoenix front. A lot of scraping, however it never found your pony nor any baleen)

On that side note, they're still having trouble with the oven doors on the TEGA instrument. They're acting under the assumption that the next attempt will be the last with it, so they're perfecting their delivery technique to minimize sublimation. I think there should be more news soon.

What program do you use for all those color composite manipulations you do?

[henk21cm]

I found this at ESA... more images of Echus Chasma...

The crater that is prominently visible in todays APOD is not easy to find in the ESA image. The coordinates of three craters in the JPG from ESA are:

• The main crater is right on the lower edge: (H, V) = (260, 1495). It is hardly visible. Todays Apod image has been snapped further to the East (below).
• The eye of emc's whale: (H,V) = (480, 1360), about 10 km to the NorthWest. (North is to the right)
• The crater with the Northern white radial stripes is at (H,V) = (580, 970), about 15 km to the West (distance to the eye)

The area in southern direction (left) has indeed a darker shade of brown than the area to the north. Judging from the shadow, there is a ridge or wall, which separates the dark brown from the light brown. Sorry if it is not brown, colour recognition is not my strongest asset.

[neufer]

According to http://www.space.com/scienceastronomy/h ... 40319.html ...

"blueberries" ... are, for the record, gray in color

<<In the RGB color model used by computer displays, it is created by mixing equal amounts of red, green, and blue light. Images which consist wholly of neutral colors are called monochrome, black-and-white or greyscale. Most grey pigments have a cool or warm cast to them, as the human eye can detect even a minute amount of saturation. Yellow, orange and red create a "warm grey". Green, blue, or purple, create a "cool grey". When there is no cast at all, it is referred to as "neutral grey".>>
http://en.wikipedia.org/wiki/Gray_(color)

[apodman]

According to http://www.space.com/scienceastronomy/h ... 40319.html ...

"blueberries" ... are, for the record, gray in color

<<... Yellow, orange and red create a "warm grey". Green, blue, or purple, create a "cool grey". When there is no cast at all, it is referred to as "neutral grey". ...>>

Surely you've heard of "blueberry grey".

[ta152h0]

maybe MARS simply shrunk due to a long ago cooling event and this is the location for a weak structure ?

[henk21cm]

On that side [Phoenix] note, they're still having trouble with the oven doors on the TEGA instrument.

Yes, read about that on the JPL site. These scraping tests gave me the impression that the acquisition of a decent sample was a lot harder than anticipated, which is strange, since NASA will not likely send a lander to Mars without a decent test with frozen soil, if such is anticipated or at least the joyful expectation of the scientists involved.

What program do you use for all those color composite manipulations you do?

That is called Matlab. It is a kind of programming language specially meant for visualization of data, images included. For clarity, the program i wrote is listed below in the code section. It is very straight forward.

Code: Select all

function chasm
orig_image = imread('..\images\chasm.jpg'); % Read the image

new_image = orig_image; % Copy the image
%	RGB numbering
r = 1;
g = 2;
b = 3;

%	Exchange red and blue
new_image(:,:, r) = orig_image(:,:,b);
new_image(:,:, b) = orig_image(:,:,r);

figure(1);
image(new_image);   % Visualize it

%	Original image
figure(2);
image(orig_image);

%	Rotate RGB
new_image(:,:,r) = orig_image(:,:,g);
new_image(:,:,g) = orig_image(:,:,b);
new_image(:,:,b) = orig_image(:,:,r);
figure(3);
image(new_image);

%	Permutate BG
new_image(:,:,r) = orig_image(:,:,r);
new_image(:,:,g) = orig_image(:,:,b);
new_image(:,:,b) = orig_image(:,:,g);
figure(4);
image(new_image);


%	Use the blue image    
new_image(:,:,r) = orig_image(:,:,b)-30;	% darker
new_image(:,:,g) = orig_image(:,:,r)-30;	% darker
new_image(:,:,b) = orig_image(:,:,g)/3 + orig_image(:,:,r)/3; % blue1/3 

figure(8);
image(new_image);

%	Grayscale image
figure(7);
image(orig_image(:,:,3));
colormap(gray(256));

%	RG as the Blue image, B less blue
new_image(:,:,r) = orig_image(:,:,b);
new_image(:,:,g) = orig_image(:,:,b);
new_image(:,:,b) = orig_image(:,:,b)-20;
figure(9);
image(new_image);

return;

From what Art Neuendorfer has reported, maybe todays APOD image we are looking at is a real (false) colour image, whereas the former images of Mars are 'heated' grayscale images, with a flavour of brownish orange, which makes us think it is a colour image. That could explain why my images 8 and 9 looked more 'natural' than the other ones.

[Baggins]

Hi all,

I've been collecting APODs for about a year now but did not know that there was a community forum to discuss these kinds of things and comment about the APODs. I'm not scientifically educated only interested in our solar system and universe.

With that said, the general concensus by scientists and even the caption suggests that this chasm once contained a vast amount of water and/or lava. By the looks of it to me............it seems to be more of a huge crevice opening up beneath the top layers of soil and all the material just dropping vertically down into the hole. There doesn't seem to be the lateral movement of the material down the trench that water typically does to soil in liquid. The different color material (whether red or blueish) on the surface looks like it just fell vertically and stayed there.

Am I looking at this correctly or should I just stick to what I know. Some pictures that I've seen of the closeups of the surface of Mars seem to show water weathered rock but I honestly don't see anything "wet" happening in this chasm recently or eons ago.

Thanks for the interesting discussion. I'll be back!

Regards,

Brett Bagley

[NoelC]

Why is it a given that the base of the chasm was covered in Lava?

Couldn't the flat bottom be explained by millions (billions?) of years of dust accumulation?

-Noel

[MSpanke]

The parallel chasms can also be explained by a deep underground crack in the crust. What caused the crust to seperate can be explained by a number of geological acivities. As sand seeps into the crack the avalanches on the cliff sides widen the trench. No water is needed to explain the larger feature here.

[henk21cm]

Why is it a given that the base of the chasm was covered in Lava?

Couldn't the flat bottom be explained by millions (billions?) of years of dust accumulation?

Good question. When you compare the plateau with the chasma, you will notice little or no impact craters. That suggests a relative young surface. Even fine dust will show impact craters, although influence of wind will erode an maybe erase those craters partly. Storms might even blow the chasma clean from dust. You might remember vast dust storms in the early 70-ties, compromising the explorations of Mars.

The absense of impact craters does neither proove nor reject Bretts remark that the bottom of the chasma was filled by the top layer, e.g. when a caldeira collapsed. The rilles at the top of the cliffs suggest flow of material, either dry or wet. The pattern of the darker material to the right of the central crater at the plateau suggests either a collapse of the plateau or a slow gradual flow of the dark material.

A lot of suggests: "It could have happened". We need more certainty. How? The caldeira at Yellowstone national park suffered a huge collaps, an odd 600 kyears ago. Vegetation will hide some of its key features. Maybe someone of us has (geological) images of the results of that collaps, showing similar symptoms.

[ta152h0]

I would love to see some guys in a UFO bring their photo album. Before you flame me, I am a regular guy having some fun here, not drunk. And no, i don't believe those things, until I see one, and photograph it clearly, not fuzzy. I saw a movie ( in outer limits I think ) that starred an airplane going thru a time continuun, trying to find LaGuardia airport, and intead circling a jungle replete with dinosaurs.

[Bad Buoys]

Nope. I feel that the chasma is filled with water even more. It may be covered deeper with insulating soil than that which we saw under the lander but look at that surface. Those look like leads which have opened at some time in the past and refrozen; just as they do in the Arctic. And with experts thinking the cliffs were formed by water, it makes even more sense for the valley to be full of the same. At minimum there must be a deep sedimentary layer from so much water having carved those cliffs in the past. I think water on Mars is going to be found to be much more prevalent than we've ever thought.

And an ice surface would also show craters. That is unless Mars also goes through global warming and cooling cycles much as the Earth such that liquid water occurs every tens of thousand years and thus this surface is remade. Our Earthly cycles are dependent upon precessions of our orbit and pole declination. Atmospherics only modify this base cycle. Mars and the other planets are probably similar though we haven't even started any measurement to track these unpopulated planets. After all, look how little we know of our own.

[henk21cm]

I think water on Mars is going to be found to be much more prevalent than we've ever thought. And an ice surface would also show craters. That is unless Mars also goes through global warming and cooling cycles much as the Earth such that liquid water occurs every tens of thousand years and thus this surface is remade. Our Earthly cycles are dependent upon precessions of our orbit and pole declination. Atmospherics only modify this base cycle.

As fas as i understand, you base your idea that the Echus Chasma is filled with frozen water on the similarity between ice sheets in the arctic and the surface of the Chasma. I do agree on your remark that a surface of ice can have craters, the craters on the Jovian moon Europa confirm that hypothesis.

About the glacial ages, the inclination of Mars' rotational axis is similar to that of earth, although the excentricity of Mars' orbit is more than that of our planet. Since the distance between Mars and the sun is larger than between earth and the sun, Mars' precession period is considerably longer than for earth: 170 kyear (25.8 kyear for earth). Glacial cycles -if any- will last longer.

Next the influence of the sun on Mars is less than on earth. As a result the temperatures at Mars are considerbly lower than on earth. Moreover the climatological influence, which in your vision is of less importance, is according to paleogeologists, e.g. Oerlemans, a major factor. The much debated and cursed 'greenhouse effect' is the key player in the initiation and ending of glacial periods. Without the greenhouse effect the temperature on earth would have been considerably lower, only allowing (the currently known) vegetation in the tropics.

Before us humans started to use fossil fuels for our work (we have used wood and coal for heating purposes for ages), the amount of greenhouse gases was predominantly controled by vulcanic activity. About 0.5 Gyear and 1 Gyear ago our planet was completely frozen: commonly known as "snowball earth". Since the feedback mechanism: absorption of CO2 by the tiny creatures (like plankton and foraminifera) in the ocean was no longer possible or substantially hampered, while volcanoes continued spewing CO2 gas, the level of CO2 rose to an astonishing value: between 1 and 10% (compared to the current 0.035%). That ended the snowball earth periods. Similarly the greenhouse mechanism is thought to be co-responsible for the ending of the latest glacial periods, about 100 kyears ago.

On Mars some volcanoes have been identified, notably Olympus Mons. The smoking gun of recent volcanic activity is however lacking, nor did i read news about recent volcanic activity on Mars, in contrast to Io. A reasonable assumption might be that volcanic activity on Mars is low, or the lads at NASA have been picking their noses in stead of analyzing images.

So far, most ingredients for glacial cycles are present, although not all active. Your idea might be feasible so far. There is one major aspect that breaks the similarity between Mars and earth: the difference between the freezing temperature of water and the respective average surface temperatures. On Mars the average surface temperature is an odd 30 K lower than on earth. Here on earth a decrease of 10 K in average tempreature will trigger an ice age. On Mars the average temperature is thought to be too low to allow for a "thaw age".

I do agree with you that high counts of impact craters in the bottom of the Echus Chasma are lacking, which suggests a recent (in geologicals terms so to say) origin.