Mars Rocks! (now APOD 26/01/2006)

[drrocks]

My question is now; are we going to find out if the light tone is basaltic or a precipitate?

You mean the rock core or the coating? I don't think there's much doubt that core is rock, what kind is in doubt, but since it appears to be hexagonal, basalt would be almost certain were it not for the fact that it's lighter that almost every other rock around it. The white/really light stuff is something else. Ice (CO2 or H2O) has been suggested, but it would be really odd to have ice under a rock sitting in an environment with no other occurrences in sight.

Astronton (sorry if I got that wrong, I'm new here and don't know if I can go back to more than 1 post in replying) suggested that there are other such rocks and indeed blowing the scene up to pixelated chaos there are a few that may be chunks of the faceted material, although most could also be sun-angle phenomena.

I'm no Mars geologist in spite of teenage dreams 40+ years ago, just a garden variety Earth one, so all I gotta say is that from all the Mars pics I've seen this thing is unique.

[astroton]

Welcome to the forum DrRocks. Astronomy is science where we are just breaking grounds out side our gardens.

The rock that I refer to is not very far from the rock in the discussion. Without even zomming in you can make out the shape and make up to be very nearly to the one being discussed. Funnily enough where the coating on the main rock is white this one has black. Unless, it's refrection or shadow or something of the sort causing the effect.

[S. Bilderback]

I can guarantee that the light portion is not H2O or CO2, neither one would last more than a few hours, but the dark portion is definitely basaltic. The light portion must be either the bedrock salts or a volcanic ash, it depends on where the rock originated from - how and how far did it travel to find its present location.

[nstahl]

So it really hasn't occurred to any of you that this is either Martian poop or just possibly a Martian egg (with Deja Thoris standing, spear in hand, behind Spirit in case of threatening activity)?

[makc]

why is it all alone?

The two toned stone is not alone...Here is the link to my zoom in....look at pic 1.

Since your link says "inaccessible", here's my zoom in.

[drrocks]

Could certainly be fragments.

The more and more I play with it, looks like the white stuff is ablating on the right side, if not accumulating at least not ablating so fast on the left side. Wind? Other indicators aren't that convincing.

What do I do re the "inaccessible" thing? What's BBCode? Sorry for the dumb newbie questions..... Long as I've been on the 'net (since it was before the 'net!) nothing should be new, but something always is![/quote]

[kovil]

The one o'clock rock ! looks to have a color change, but the 9 o'clock rock looks like light reflection of some kind, likewise the 8:30 rock.

The rock halfway below the one o'clock rock and the bottom of the picture frame in your zoom in; looks to have the color change across the uniformly illuminated top, and thusly is a best candidate for no lighting tricks.

Lots of rocks here have a surface difference!!

Good site for investigation.

Are they grinding samples for analysis?

**Watch out for that Crocodile Rock just outside the photo frame !

[borg]

It is a fossilised Martian skull. The vertebral sheath articulation is clearly visible. We studied their anatomy a long time ago.

[Aqua]

Just when yah think Mars Rocks couldn't get any stranger..... there's today's (01.30.05 - Sol 736) Spirit microscopic image(s) of one of the 'bubbly' looking dark coloured stones near the rover.

http://marsrovers.jpl.nasa.gov/gallery/ ... 56M2M1.JPG

This stone, like the other 'pitted looking' dark coloured stones in the area 'shot thru' by volcanic gases? or perhaps have been exposed to acidic erosion(s)? OR, might they be meteor fragments?

Any MER team members out there with answers?

[BMAONE23]

This is an excellent exapmle of a possible fossil on Mars. The Trilobite like imprint is, in my opinion, remarkable. (See the first 3 or 4 images on the page.) The others (squid, etc.) on the website are more subjective.
http://www.xenotechresearch.com/marsx.htm

[makc]

I just noticed this thing become an APOD.

[jeffab]

In reply to drrock

You mean the rock core or the coating? I don't think there's much doubt that core is rock, what kind is in doubt, but since it appears to be hexagonal, basalt would be almost certain were it not for the fact that it's lighter that almost every other rock around it. The white/really light stuff is something else. Ice (CO2 or H2O) has been suggested, but it would be really odd to have ice under a rock sitting in an environment with no other occurrences in sight.

Based on my limited knowledge from my undergrad geology studies so far, I would say that this is the most likely/accurate interpretation of this particular rock. The most fascinating thing that jumped out at me when I saw the pic on APOD was that the center, darker rock appears to show crystal faces. I agree that hexagonal is the most likely, but the exact symmetry is hard to determine without additional photo angles.

If this is the case, the center rock is likely igneous... the result of very slow cooling of relatively deep magma. The light, encasing material is obviously less resistant to weathering but it's difficult to say exactly what the material is, though it seems likely not to be either ice or solid CO2. As others mentioned, it could be volcanic ash or some sedimentary material that accumulated around the center rock long after the volcanism stopped.

I hope that this rock will be visited in depth in future studies of the rover photos, as it does seem to be unique as well as an important indicator of geologic processes on Mars.