Don't go for it, Dan. Sure, it's just a trillion dollars now, but give it a few months, and he'll be needing another 100 million for this and 200 million for that. The project time line will get pushed back, and who knows if we'll even still be using iron and steel by the time he's ready to launch. If it was me, I would be looking to invest in an enterprise that looked to Mars as a dumping ground for our excess dihydrogen monoxide. Do you have any idea how many people die each day as a result of contact with this substance?

Right, the blasted stuff keeps getting in my Scotch.

Phil

This meteor is pretty sweet . But I hope we will not waste time around this place.

So, here is the Sol 2022 navcam pan centered on Shelter Island :

This is bigger than BI, right ? More than 2X ?

SI is smaller than BI. There's a little blurb on the jpl site.

Yeah, 47 cm across for SI versus about 60 for BI.


Thanks, fredk. My guess from the sol 2020 images was a little over 3 meters off. I was planning to refine the location when the navcams came down, so it was nice to see that you had saved me the trouble.

This rock is probably not quite large enough to be resolved, though with its shadow and other local effects, who knows.

Then you're drinking the wrong brand of Scotch.

Here is a processed NAVCAM image of the 'sheltered island' meteorite.
Click to view attachment
let's drive!
cheers

here is a processed PANCAM image of 'sheltered island' meteorite

Click to view attachment

cheers

Think so too, because there seems to be at least one more in sight in the upper right of the pan...

http://www.unmannedspaceflight.com/index.p...st&p=147061

SI is partially buried in the dune. If it wasn't for the ripple, it would be on the surface. This makes me wonder what else lurks beneath this wind blown stuff.

Managed to work on Shelter Island a little more...

Click to view attachment

This is a seriously-beautiful meteorite... if this had been found on Earth it would be a museum centre-piece, with all those features...

No argument there. Makes me wonder how many great rocks like this have been quickly destroyed (relatively speaking) by Earth's voracious weathering processes.

<shakes fist>WAAAAATERRRR!!!!!....

Do you think of an evident reason why there's "so much" meteroits in this area while none has been noticed since the one near Endurance? (was it Bounce rock?)

Why so many here?

...Perhaps the break up of a larger meteorite. Maybe these are parts of the same single streak in the Martian sky. It might explain why Block Island looks the way it does...the weird looking cavities as if untouched by the forces of atmospheric entry. There are a few small craters that appear relatively young in this part of the plain too. Just food for thought and thinking out loud.

Heat Shield was the meteorite near Endurance. Bounce was the piece of long-traveled ejecta near Eagle (Opportunity's landing site).

I see this suggestion a lot, but all the meteors have a rounded, potato-like shape. They seem whole to me, not like a cut up potato. Meridiani is apparently a very old surface which has had millions or billions of years to collect random meteors.

edit: I really don't know a lot about the subject. Have Iron meteors on Earth been known to break up on entry? My impression is that they are pretty solid lumps, not likely to break up.

I'm with you there - the fact the we're seeing a basketball sized meteorite every couple of km (on average) isn't all that surprising when you think how long a few billion years actually is. I seem to recall reading somewhere that about 10 meteorites are recovered soon after falling on earth every year (as opposed to the total that are found but may have been in situ for a long period of time) . Ignoring scientific rigor for a minute and just thinking about ballpark numbers let's say that this is a reasonable floor level number for the number that reach the surface of Mars intact (since it has a similar land surface area to Earth). Over a billion years we're looking at 10 billion meteorites. The surface area of Mars is about 145m Sq km. It is not unreasonable to expect that each sq km should have about 70 meteorites (on average). Assuming that only about 2-3% are Iron meteorites like Heat-Shield\BI then expecting to find 1-2 per sq km isn't unreasonable. We have a sensor range of around 100m (say 50m each side of the track) where we're likely to be able to see and recognize a large meteorite. With 18km driven we've probably covered about 2 square km of surface at enough detail to be able to see these things and we've found 3 that we're certain of.

Frankly I'm surprised that there aren't many more.

I can imagine that if we see a lot of rounded metal meteorites on the surface, and that they all fit into a narrow size category, that probably tells us that they landed at a time when the ice on the surface was a certain (unknown to me, a hack) thickness that protects these basketball sized rocks, and drops them gently to the surface (maybe millions of years later), but that larger hunks of Iron drill through in the initial event and create craters.

I'm interested in getting to the big crater, but stopping along the way to catalog this hunks of Iron seems smart.

BTW, I wonder if the black rubble piles we've been seeing are also meteors that got their falls broken by ice.

Do solid chunks of iron really need to be 'protected?' And besides, how much different is it for a meteor to hit ice as opposed to loose regolith or soft rock? I don't see any way to infer that these meteors landed on ice. Isn't the current thinking that they landed at a time when the atmosphere was thicker and slowed them considerably before impact?

Maybe there was ice and maybe not. I just don't see it as being necessary [or even indicated] to explain the current situation.

While there are obvious differences in the nature of an impact into ice, sand, soft or hard rocks I suspect that only impacts into hard rock noticeably affects the initial survivability of the meteorites. Landing in ice and becoming embedded protects meteorites on earth (I think) because we have an extremely dynamic surface environment but on Mars I suspect that simply being exposed on the surface is a far more benign long term environment - the internal mechanics of ice sheets over geologic time scales are pretty brutal after all.

I would think that the density of the atmosphere would be a far greater determinant for meteorite EDL survival since that largely determines terminal impact velocity for objects of this size. IIRC, there were a few rather offhand comments on the JPL site speculating that the atmosphere must have been significantly thicker when BI hit.

Bottom line: These guys are probably really, really old & they're being slowly exhumed (& reburied) as the dunes move around.

I love your line of reasoning Joe, and I think you are spot on. What might add to the unexplained gap is the sand dunes. Objects the size of Block Island and Sheltered Island, being a significant portion of the size of the local dunes, are probably big enough to interfere with the air flow and sand movement and thus are probably always visible. Smaller objects like Heat Shield Rock, and smaller may in fact have a chance of becoming buried by the migrating sands, or might even be just out of view behind a dune. As it is Block Island is approaching the limits of observability from HIRISE. And that doesn't even take into account the survivability of a less stable meteorite like a chondrite. What might one of those look like after thousands or millions of years (cobbles?)

I suspect that there are many more meteorites at Meridiani that a six foot tall person trudging back and forth across Meridiani might easily spot or uncover with a few kicks in the sand.. And if you go back over the HIRISE images at random you do see discontinuities in the sand dunes that seem out of place, as well as little smudges and whatnot that could very well be more "Heatshield Rock" sized objects. I would venture that a useful study could be gleaned from a half dozen identical HIRISE images taken under optimum conditions of the known Meridiani environs and stacked for super-res properties. That might provide a chance for a careful inventory and study on the numbers of suspect objects.

Not so much that the hunk of Iron need protecting as Mars does. What size crater would this hunk of Iron have left? That crater isn't evident.

That's something I've been wondering about. A sample size of three isn't much, but from earth experience there should be dozens of stony meteorites to go with them (assuming they aren't part of a single fall.) Some completely amateur speculation:
- Maybe conditions were such that iron meteorites could survive entry/impact but stony meteorites in the same size range shattered ?
- Maybe they are there, and we are just missing them because they look don't stand out as much. Probably true to some extent, but I don't recall anything block island sized that didn't look like local bedrock.
- Maybe the stony meteorites did survive landing, but erosion or other processes break them more quickly than irons ?

My WAG is mostly a combination of the first two. I did find references to some cobbles being identified as probable meteorites:
Origin of Rocks and Cobbles on the Meridiani Plains as Seen by Opportunity 37th Annual Lunar and Planetary Science Conference, March 13-17, 2006, League City, Texas, abstract no.2401
Cobbles at Meridiani Planum (pdf) Mars EPSC Abstracts, Vol. 4, EPSC2009-512, 2009

Oppy passed by a couple of potential meteorites shortly before reaching Beagle Crater

This one was listed as genovesa in the database (image from sol 875)
Click to view attachment

It and another similar rock were also imaged on sol 870
http://marswatch.astro.cornell.edu/pancam_..._L257_pos_1.jpg
http://marswatch.astro.cornell.edu/pancam_..._L257_pos_2.jpg

Yes, that is a good reason to postulate an impact in ice. There is also the possibility that there were craters that have since worn away to reveal the meteorites. As far as I can tell, the mainstream thinking seems to be that they were slowed by the atmosphere enough to land without forming a crater.

As I see it, the ice and soft landing hypotheses have theoretical evidence: Billions of years ago Mars likely had a thicker atmosphere and glaciers and other ice fields. And the eroded crater hypothesis has physical evidence: The layer of loose blueberries that, to me, is proof of layers of rock long since worn away.

I understand that some think the berries could have formed in ice but I have never understood that, since we can see berries still in the remaining rock layers, apparently where they formed. The possibility of impact surge aside, of course.

Wow. That fills in the distribution map a little between Heat Shield and the latest ones, BI and SI. Assuming that those passed by are indeed iron meteorites, and that image sure looks suspicious.

This paper describes the cobble, Barberton, which is also mentioned in your second reference along with other possible meteorites:
"Barberton was found just beyond the southern rim of Endurance crater. Its composition is... similar to chondritic meteorites."

First real try at a Shelter Island colour view...

Click to view attachment

Beautiful! SI's photogenic as hell; looks like a set prop from a 1950s SF movie.

Mini-gallery of pics here: http://roadtoendeavour.wordpress.com/2009/...-shelter-island

My own takes on Shelter Island. Agreed, it's definitly a luvery meteor



Stu, very nice galery

I'm starting to wonder if I spend too much time looking at these images.

I'm sure a lot of us are guilty of the same, Dan!

I wonder how far SI extends under the sand:
Click to view attachment

3D (departure?) image of Shelter Island here... http://twitpic.com/kalis (there's a 3D poster there, too)

Unless this meteorite arrived here rather recently, it probably is sitting on the bedrock below the sand. Although unlikely, it is tempting to imagine that it could be partially embedded in the bedrock.

I am hoping we get some closer images. I don't see any Widmanstatten patterns as were apparent on Block Island, but if we do find them it would strongly suggest Shelter Island and Block Island were once part of the same impactor. We can see apparent inclusions in this rock (see attachment). Although they look like inclusions, they don't appear very different spectrally from the rest of the meteor.
Click to view attachment

EGK, maybe by cleaning the dust of Shelter Island you will be able to have the genie ? And let Oppy exauces 3 wishes :
- have new boggie system for roving ;
- have a new robotic arm ;
- be teleported to the nearside of Endeavour Crater.

Mmmmh?? What? You're calling the doctor?

So!

The Sol 2024 view, with selected frame to show SI in his context :

And a pancam insertion to show his context :

No worries, Ant; nobody's gonna take you to the funny farm when you keep cranking out gorgeous images like that!!! Wow!

Stereo pancam view of most of Shelter Island:
Click to view attachment

If you look at it from another site, it is no longer such well shaped. Could be also a fragment from a broke up body I guess.
https://qt.exploratorium.edu/mars/opportuni...cam/2009-10-05/

There're falls of irons on Earth where there is a strewn field. One of the known biggest is
http://en.wikipedia.org/wiki/Gibeon_%28meteorite%29
http://www.meteoritemarket.com/GNinfo.htm

How dense the atmosphere on Mars had to be proper then, I don't know.

In Nov 1957, an iron meteoroid with an estimated mass of 900,000kg exploded above Sikhote Alin in Russia, showering the ground below with around 100,000kg of shrapnel-like fragments. I have a small piece, but this pic of a much larger specimen gives a good idea of what can happen to a big iron meteorite when it takes on Earth's atmosphere...

http://www.towercrystals.com/meteorites/si...es/RHB_4074.jpg

I think it's more likely that BI and SI and the others we've seen on Meridiani were once parts of the same rocky-iron meteorite. The cavities we see are the result of both the atmospheric ablation of softer, rockier material and erosion after landing by the martian environment.

So there are! Here is a descriptive list of some.

It's interesting to see how important strewn fields are to the meteorite sales trade.

I guess it is possible that Meridiani is the site of a Martian strewn field.

Or more likely, several overlapping strewn fields.

Next "island" coming into view near the top of this drive direction pancam:
http://qt.exploratorium.edu/mars/opportuni...C4P2421L6M1.JPG
Could it be our next stop?

Good grief. Meridiani Meteoritefest '09?

This is all beginning to feel like some kind of dream I had when I was a kid!

Can you guys tell how big that is compared to BI from this shot?

Same ballpark, but seemingly light in color rather than iron dark.

Yeah...I was gonna mention that too, Shaka.

At this point, an anomalous native Martian rock would be a novelty. Or maybe it's a stony meteorite, who knows? (We're gonna find out...hee, hee, it's like bein' a kid in a candy store!)

BTW, whatever happened to Sugar Daddies?