- http://www.msss.com/mars_images/moc/2006/05/12/

Very interesting image, SigurRosFan.

A bit puzzling, because of bottom lighting. I managed to see it correctly with head tilted horizontally to the right. The left part of the image appears lower, and the slope in front of us.


What is interesting is th fact that the dark streaks don't stop at the borrom on the slope, but somewhat continue on the flat bottom. This is an evidence that it is a dynamic process, occuring at high speed, not a slow crawling process.

On some parts of the bottom at the foot of the slope, the ground shapes appear slightly obliterated. This is an evidence that these dust avalanches were numerous in the past, but that they carry little dust at a time. This conforts the theory as what they are formed by falling dust accumulating on the ground.

At last, there are many streaks of roughly the same age here. Perhaps a quake triggered them all in the same time.

Acheron fossae is a puzzling small zone of highly fractured terrain showing many horsts and grabens*, north of Olympus mons. It seems recent, and perhaps still active. It is part of the overall fault belt around Tharsis plateau.

*horsts and grabens: parallel parts of terrains, uplifted or subsided, between parallel faults.

The picture is puzzling.

I don't think that these black strips are the product of Dust Devils neither of gullies.

The most probably guess is that between the bottom and upper land, at the middle zone is of other composition, maybe, some ice liquid was melted and the it carried out the naked and dark land to down. The flow direction is from right to left of picture.

However, I seems that the action of melting liquid is not the only factor but also of aeolian factor. This might be the main source that causes this phenomen.

Rodolfo

The most comonly accepted explanation about these "liquid like" dark streaks is that they are dust avalanches. The process is as follows: every day a thin dust descends on mars ground (which was carried in the atmosphere by dust devils and large storms). This dust is light colored, a bit reddish. It accumulates on slopes too, but when it reaches beyond the equilibrium point, an avalanche occurs. This avalanche may be very thin, about a some millimetre dust layers. But when it flows, it left the darker terrain under to appear, creating these black streaks which strangely look wet, but are not. It is in the frame of this explanation that I commented above.

Possibly a candidate terrain for these manufacturers ?
http://www.spacemodelsystems.com/terrains.html

Now I can see better that the avalanches are due to the bonding of dust by somewhat. It might be due to humidity. I have observed after I have caused an avalanche of sand of a dessert. The shape of avalanche of sand looks very similar to the ones of picture. Then I recognize that its shape is of avalanche of sand or dust and not of liquid. The avalanche of sand is not of pyramidal shape but very vertical and narrow shape.

Rodolfo


Phil, very interesting WEB! computer simulations of terrain model.

Rodolfo

Don't know if Kees is on this forum, but he's a Dutch guy with an interesting website:
http://www.space4case.com/index/index1.html

Beautiful renderings, but with all those light effects I think that Zaphod Beeblebrox *might* have described some of the images as 'needlessly Messianic'!



Please *don't* let Phil Stooke see this URL - it'd be *bad* for him (gave me quite a turn, too!):

http://www.spacemodelsystems.com/globes.html

Bob Shaw

WOW! I hadn't seen this website before!

Me want! Me want RIGHT NOW: http://www.spacemodelsystems.com/tohil.html

"Please *don't* let Phil Stooke see this URL - it'd be *bad* for him"

I'm not that emotionally fragile, Bob.

Phil

Phil:

Well, I certainly am!

My desk is, anyway...

Bob Shaw

I can only add athat I recommend it too, used to have one of Kees illustrations of Kasei on my desktop for nearly a year. Nowadays im here I change more often for some odd reason!

It is a great website, for the moment I'm awaiting the re-edition of the two-foot Mars globe ... love to have one of those !

Oh, man...that is so cool!!!! Me want right now too!!!!

Perhaps, but not all scientists are convinced that they are dust avalanches:

http://www.space.com/scienceastronomy/stre...ars_021211.html

Independent researcher Efrain Palermo had also published a good paper and compiled an excellent "stain map"; he presented his findings, along with Jill England, to the National Space Society in 2002 and the Mars Society Convention in 2001:

http://palermoproject.com/Mars_Anomalies/%...ySeepsPaper.pdf

http://palermoproject.com/Mars_Anomalies/MarsStainMap.html

http://palermoproject.com/Mars_Anomalies/updated_images.html

And no, they are not affiliated with Hoagland / TEM, before anybody asks...

I might have some other references also, but I need to find them again. There has been just as much debate about these features as the other gullies.

And by "not affiliated with" you of course mean a regular collaborator, having even appeared on stage with him at one of Hoagland's seminars: http://palermoproject.com/Mars_Anomalies/H...New_Mexico.html

That said, Efrain's work isn't the usual garbage that comes out of the anomalists group. He's capable of doing reasonably competent research for an amateur astronomer.

Bad company doesn' t *have* to mean bad science, but it's sad if a bit of quality scientific work is ignored because of one's natural distaste for cultists (except for Cthulhu, of course! Yum, yum!). Sadly, the merest mention of the H-word makes my otherwise notoriously open mind snap shut with a resounding snap!

Bob Shaw

Ok, I just meant that Palermo is not part of TEM itself, he's independent.

I think he has done good work, and along with the other scientists referenced in Space.com, etc., has provided "reasonable doubt" that all the "stains" are simply dust avalanches. Some probably are, but I'm not sure they all are.

There are good studies that have been done by some "anomalists" but unfortunately they tend to usually get ignored and painted with the same brush as it were, as Hoagland, etc.. That's why I believe in evaluating anyone's work on an individual basis.

Studying anomalous phenomenon or arguing for non-standard hypothesis don't make us nutters. It is even a fundamental freedom to be able to do so.

It is sad that so many scientists are closed to anomalous phenomenon or non-standard hypothesis, but I must say that they are not the worse ennemies of those who study these phenomenon. The worse ennemies are the nutters who spread so much garbage around the (few) serious works into these domains and discredit all the (few) serious works.

For instance, it is an independant private UFO studier group, the CUFOS at Chicago in 1989, which enquired about the Roswell case and demonstrated it was entirely bogus. But who know about this demonstration???

But nutters themselves would be completely inoffensive and ignored, if they were not given so much publicity by certain medias...

We should look for Zebras on Titan - if and when we have enough resolution - if avalanche are the cause, these features should be very sensitive to any movement of dust on or near the surface, and give us a good feel for how mobile the surface of Titan is. (I'm still wondering if the cat scratches / dunes are frozen or active.)