[X] My Assistant

[stewjack]

Now that we know where we are going, I thought we could use a topic about our future route. I hope that a few images will get the rover rolling - downhill.

READY START

BACKGROUND
------
From Steve Squyres Misson Update
Octoberber 4, 2005

Extending eastward from the summit of Husband Hill is a broad ridge that we've named Haskin Ridge. It trends ENE from the summit, does a little dog-leg to the right, and then trends ESE for a bit. Right at the dog-leg there's a pretty steep step, which we're not certain we can get down. So we're going to descend the upper portion of the ridge, right to where the step is, and assess the situation. If we can see a safe route, then we'll continue down onto the lower portion of Haskin Ridge.
------

My Image of Haskin Ridge
I tried to get the best image of Haskin ridge that was available, and this is a crop from a true color TIFF summit panorama, located on the the Cornell Pancam web site. I converted the tif file to a gif file to save some download time.

Warning : File Size : 1.7 MB
Cornell True Color Pan of Haskin Ridge

Reference
WEB page of Husband Hill Summit Panorama
Warning: File Size : 80 MB !!!!
Preliminary Spirit Pancam of "Husband Hill Summit" Panorama

Jack

PS If you can't see the "steep step" that Squyres mentions - try this orbital image. I believe that the "steep step" is the dark shadow cutting across the ridge that is located directly under the word CRATER. I think that it is also visible in the true color pancam image, but it is less obvious.

Orbital View of Husband Hill and Basin

[edstrick]

The yellowish cast is present in the entire outer portions of the image. This results from wavelength dependent vignetting or more likely wavelength-dependent center-to-edge shading in the CCD detector of the camera.

The relatively blue soil in the hollow under the rock is real and is probably well sorted and highly mobile basaltic sand, probably some of the same stuff as the dark patches on the hill to the northeast, and forming the "Ultreya" sandsheet on the south side of Husband Hill.

And that rock is a classic piece of chewed up don't-walk-on-it-barefoot nastyrock.

[Bill Harris]

That explanation is along the lines of what I speculated; having tilted at windmills a couple of times recently I decided not not try to bankrupt my reputation at 4-in-the-am.

A source for dark mobile basalt sand... another piece for the Ultreya puzzle. And it is probably the same material in the rippled dark sand of the Eastern Basin.

--Bill

[edstrick]

"basaltic" sand clearly can go for very long distances on Mars. Just look at hundreds-of-kilometer long dark bluish wind streaks trailing down wind from sand dune masses in craters in the Oxia Palus albedo region north of Meridiani. And this sand appears able to travel far without rapidly abrading "dust" based sediments and obliterating them.

Much of our desert sedimentology... much... *MOST*... is from earth where finer silt and clay sized "dust" tends to either get washed down rivers into seas or blown off continents into oceans. Either way, it tends to be taken out of circulation and turned back into rock or ocean-floor ooze.

There is millions to hundreds of millions of years of eolian sorting and recombining and lightly cementing and disaggregating sediment on mars that we've barely imagined.

[helvick]

There is millions to hundreds of millions of years of eolian sorting and recombining and lightly cementing and disaggregating sediment on mars that we've barely imagined.

I've never quite figured out what erosion mechanism would be needed to make any significant volume sand like material on Mars rather than very fine dust dust. Actually what I'm thinking is do we have any idea what sort of particle size profiles are probable and in what sort of volume? Or does the distinction need to be significantly altered because we are dealing with an environment with a lower gravity and significantly lower atmospheric pressure\density.

Obviously billions of years has resulted in erosion on a massive scale but my gut feeling is that the overwhelming bulk of that should be nano\micron scale dust and that true sand scale particules would only arise as a small fraction of impacts and volcanic debris. I seem to recall reading somewhere that most terrestrial sand is made by glacier action, I'd really like to know if that is pure hokum or not.

[ElkGroveDan]

I seem to recall reading somewhere that most terrestrial sand is made by glacier action,  I'd really like to know if that is pure hokum or not.

It's hokum. Sand-sized particles are just another step on the scale of erosion. It's been years, so I'm not going to tread into the geologic specifics this early in the morning on my first cup of coffee. However, the best way to disprove this broad assertion is to simply examine localized sands eroded from chemically unique local rocks in areas absent any evidence of glaciation in the recent geologic past. Such sands disprove any assertion that they must have migrated from distant glaciated regions.

Think of the basaltic black sands of Hawaii (and other volcanic islands). There's been no glacial activity there and the sands have clearly not been transported from elsewhere as evidenced by their composition.
Black sands

The red ferric sands of Southern Utah are another example. Though there has been glacial activity near there (though not much that far South), it's clear that the growth and presence of those sands is local, recent, and ongoing.
Coral Pink Sand Dunes

[helvick]

Thanks Dan, I thought it was far too simplistic.

[peter59]

Very, very long drive today.

2N184525680EFFAJ00P0685L0M1.JPG
2N184525716EFFAJ00P0685R0M1.JPG

[Nix]

That looks good !

Nico

[dot.dk]

Bye bye Husband Hill

http://marsrovers.jpl.nasa.gov/gallery/all...00P1312R0M1.JPG

[TheChemist]

I've made a quick navcam stich, and now the question is : where is Spirit located now in jvandriel's panoramas from higher above on the hill ?

Attached thumbnail(s)

 

[tty]

The red ferric sands of Southern Utah are another example.  Though there has been glacial activity near there (though not much that far South), it's clear that the growth and presence of those sands is local, recent, and ongoing.
Coral Pink Sand Dunes

I suspect that most of those red sands on the Colorado Plateau are actually recycled from the red Triassic desert sandstones in the area which accumulated at a time when there most likely were no major glaciers anywhere on Earth.

Incidentally fresh glacial sands have a number of peculiarities, most notably that the grains are rather rough and angular which is the reason that Scandinavian sand is actually exported to the Middle East and North Africa (sand used for moulds when casting metal should have angular grains, desert sand hasn't) .

tty

[jaredGalen]

This attempt at a guess makes me wish I had my Photoshop on this machine

We've driven a heap!....I think

Is she somewhere here??

Attached thumbnail(s)

 

[Phil Stooke]

I don't have an exact match, but I think Spirit would have to be a bit north (left) of JaredGalen's point, and probably not quite so far out on the ridge yet.

Phil

[GregM]

.

[alan]

I agree with GregM. here it is in the navcam