Does it have a name?! Does it have a name?!

When I look at Concepción I can almost hear the BANG! when it was created. This crater is fresh!

ADMIN EDIT

KABLAM! It's so fascinating to see the rays of rocky debris spreading out from the crater. Any luck these rays would be sorted by depth, with top layers being more fragmented and spread further than the deeper layers, or is crater formation much more chaotic?

Actually, it has.

02138::p2551::24::6::0::0::6::2::14::pancam_Ubay_L257R167

And another one, imaged on sol 2136, is named "Anda".
Now, Rui, it's your turn to find what do they mean.

Is Concepción (bottom) really very different from Fram (top)? The pictures are not to the same scale, but both craters look to be in the same size and age ballpark. (Note Endurance crater behind Fram's right side.)
Click to view attachment
Here's the old UMSF Fram thread.

It is a little different. The main ripples of the Meridiani plains are overlapping the rim at Fram, so that you have dunes lying at the top of the crater wall. You can also see ripples on the crater floor at Fram. At Concepción, the inner ejecta field lies on top of the dunes and I don't see any small ripples inside the crater.

That's just combining what I see with what was said on Emily's blog regarding the order of magnitude age estimate.

OT:


Ah! It was a good read and a nice time to remember the old days when we though Endurance was almost beyond the limits...
This is from the above thread:

Ubay and Anda are districts in Bohol province in the Philippines

Right, forgot that the Phillippines were going to be the theme for Concepcion, thanks!

Very apropros; the archipelago has something like 7000 islands, IIRC.

For the old-school among us, here's a cross-eyed stereogram of Concepcion... it is indeed a pretty spot - will we rove to the rim?

Click to view attachment

Thanks - I really like that. Nice not to to have the distracting colours for a change.

Centsworth, thanks for digging up Fram! They DO seem remarkably similar, with perhaps the difference being age. So if Concepcion is 1K years old, how old is Fram? 10K? 100K?

And way cool to see Endurance in the background! Seems like a lifetime ago that we rolled to its edge.

I'm having trouble with these very young ages. Meridiani Planum is lightly cratered by Martian standards but it still has enough craters that I'd be surprised if the age of the surface we see was less than 100 million years, say. If that's the case, only one crater in 100 should be less than a million years old, and only one crater in 100,000 should be less than a thousand years old. As we've passed far fewer than 100,000 craters of Concepción's size (maybe more like 100?), the odds of it being so young seem very slim.

All these numbers are WAGs but I doubt that they are wrong by a factor of 1,000...

John

wohoo guys! we're once more on Mars!!
and not the Philipines Nick, Bohol man, Bohol, forgot it?...
http://www.unmannedspaceflight.com/index.p...st&p=153846

IIUC, Opportunity's tracks are already accumulating dust. To my untrained eye there's not much dust around the cobbles at Concepcion. Wouldn't even a thousand-year-old crater show more accumulation? Let alone an older one?

(not a geologist)

Craters of what age? If every impact over the history of Meridiani is the range of our sample then I'd say we've passed a whole lot more than a 100. How many "Scamanders" have we passed and not observed? I don't dispute your methodology or reasoning John but I do believe that we simply don't have enough data points or a truly thorough study and analysis. I accept that the global cratering rates and ranges are applicable on a body like the moon where erosion is essentially non-existent. With Mars in general and with Meridiani specifically, we must acknowledge however that erosion and mass-wasting ARE occurring and that the rates over a planetary time scale are far from static. Further we still have no real solid understanding of the regional variations in erosion and deposition on Mars. Evidence of impacts would erode far faster in a body of water than across a wind swept plain. Was Meridiani a long lived sea? Was that sea static or subject to eddies and currents? Or was it nothing more than a temporary swamp? I've seen some truly inspiring science and studies of Martian geomorphology over the past decade that propose intriguing answers to some of these questions, but we honestly have to admit that there are still so many unanswered questions in a region like Meridiani. I don't feel that it's possible to even estimate the absolute age of a crater like this.

I am however just an armchair observer and you are a respected professional who does this for a living so no disrespect is intended.

Thanks for the cross-eyed view. I don't always have the red-blue stereo glasses available. But this always works.

David

Rui, my apologies. Not only did I neglect to credit you with the theme for Concepcion, I did forget that the names were to be the neighborhoods of Bohol. Mia maxima culpa, man!

In evaluating Concepcion, the main efforts will be in the Geomorphology (as stated above), plus a look-see for any evidence of the parent meteorite body. (There might also be an APXS exam of the sulfur-salt pavement fragments to see if composition is changing during the long traverse.)
One of the interesting aspects of this crater is the "disturbed" look of the nearby dunes. They seem to still bear the scars of the seismic shock and the impact of debris from the impact. It is reasonable to speculate that no major dune-moving wind event has occurred since this crater was formed. There is an implication that dune-moving high wind events only occur during a different climatic period than Mars is in now, perhaps only every few tens of thousands of years (due to variations in Mars' orbit and precession of its axis). About the only thing missing from the site (from immediately after the impact) is the very fine and light white sulfur dust from the fragmentation of the pavement.

My polar version of Ant's nice panorama posted above.

Phil

Click to view attachment

No disrespect taken! Still, I *think* my point holds. Note that my WAG age for the *surface* was 100 million years. The rocks of Meridiani are likely to be three billion years old or more, 30 times older, so if you counted every crater since the rocks formed, there would be ~30 times as many as my estimate- most of them have indeed eroded away.

Thanks to HiRISE, we do have a handle on the current rate of formation of small craters on Mars, so someone ought to be able to estimate the chance that a crater of this size would have formed in the last few thousand years on the few square kilometers that Oppy has explored...

John

>Thanks to HiRISE, we do have a handle on the current rate of formation of small craters on Mars

I thought that this understanding was based on multiple MOC observations of substantially identical targets. I think I recall Malin or Edget discussing this in the hastily-scheduled (and very moving) press conference after MGS was lost. Or has HiRISE taken the understanding substantially further?

TTT

You're a messed up little rock, aren't you..?

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Ok, I finished moving some posts from this and the "route map" thread to the new "Distant vistas".
From now on: this thread for discussion about Concepcion, "Distant vistas" for talks about the sights at the horizon while we are stopped at this site and also when we continue moving forward, and the "route map" for, er, the route map and related stuff.

Do you want Concepción in color? Just wait for the next images update.

02140::p2368::21::48::0::0::48::1::97::pancam_concepcion_pt1_L257

My apologies to MOC- yes, this was done first by MOC.

John

John, I think this abstract by Golombek et al may address your question?

And continued by CTX far more than by HiRISE.

I did such a back-of-the-envelope estimate back in this post, and got very low odds as a result, and estimated that the youngest crater in the order-10 km^2 Oppy has visited is of order a million years old. I can't say anything about how reasonable the cratering rate I used was (follow the links to my source) or if better estimates are available. But Concepcion does look like quite an anomaly.

To me Concepcion looks much fresher, with all that ejecta on the rim and farther into the rays. A crater that looks closer in age to Concepcion (but still older?) is Resolution - see the image in this post for example, or other pics in that thread.

This answered some of my questions, too. It seems that the changes in Mars' orbit and axis are on the scale of 100,000 years (rather than my statement of tens of thousands), so the profound ancientness of the surface is again reinforced. Comparing Concepcion with Fram and Resolution Shows Conception to be younger (Fram has significant dune formation around its rim, and Resolution has much ejecta partially buried in dunes).

Given Conception's very fresh appearance, but with no white sulfur powder and the presence of a few small NE-SW oriented "dunelets" of very fine material, the 1000-year proposed age for Concepcion seems very reasonable.

Now, can anyone our there tell if this is a crater of a very-fast-moving small impactor, or a a slower-moving larger impactor (i.e., a primary or secondary crater)? Does the appearance of the crater give sufficient information?

I tried to make a 3D stereo gif, as I don't have red/blue glasses...
Sorry for the results. I am a bit dizzy right now
I used this software: http://stereo.jpn.org/eng/stphmkr/index.html
It's far from perfect, but it gives you a general idea. If you have problems seeing it download the file to your computer and open it with your image viewer.
Click to view attachment

Regarding the likelihood of a 1,000 y.o. crater, wouldn't you also need a more accurate estimate of how many rocks are in Mars' path? Once we're done counting NEO's, we'll have to get a catalog of NMO's!

That rate is estimated from the crater production function, which you can get at by really tedious crater counting, although there are numerous subtleties that cratering scientists spend a lot of time arguing about.

That's after they hit. If the volume of NMO's has been depleted, wouldn't that change the numbers?

Yeah, but the rate of change has to be pretty slow over time. Also, Mars may have a prima facie higher observed impact rate than Earth just because the atmosphere doesn't have anything close to the stopping power of ours, but a lower overall object encounter rate due to the planet's smaller Hill sphere. That would presumably also reduce the population of putative NMRs to some degree.

It's a complex problem with a lot of poorly-constrained variables; not seeing any easy answers jump out.

Large-scale patterns, like the creation of the asteroid belt beyond the orbit of Mars, would play into it.

L257 pancams down, yaay!

Others will do much, much better, I'm sure. I just fancied a quick go!

Click to view attachment

Images for everybody! Crater investigators and horizon explorers.

http://qt.exploratorium.edu/mars/opportuni...66P2368L7M1.JPG

looks like lots of blueberries in the rocks.

Yeah, I noticed that, too...been awhile since we've seen that. Some of those rocks bear more than a passing resemblance to Wompmay in general appearance & texture (though of course not size.)

YES, very very nice pancam's today, and the view is litteraly mindblowing !

Can't wait to made the color pan of this Sol 2140 :


Did they plan to do a full 360 ?

And a desktop picture to bring us a litte more close to Mars

OMG, Ant, mine look like they were made using *crayons* compared to yours!!!!! They're... beautiful!

(clicking sounds as Stu deletes Paintshop and Photoshop from his PC... )

Ant, I would give you a hug if I could. That is amazing.

(Interesting how we're all avoiding that one frame with the missing filter )

Oppy: "Oh just boulders around here... let's drive now further".
"Err, Oppy, what's your mission?"
Oppy: "Driving "
"And?"
Oppy: "Taking pictures of rocks:)"
"And?"
Oppy: "Analyse rocks?"
"And?"
Oppy: "Taking spectra of rocks?"
"And?"
Oppy: "Grinding into rocks ... ok, I stay for a while here."

Still at least 2/3 of the pan to add, but seeing how everyone is falling over themselves over this one...



James

All I see is Meridiani-rubble. Anyone sees a rock that could be the remains of the impactor?

EDIT: Curious. What happened to the left side of the rock? Pre- or postimpact?

Looks like the same type of rind material we saw in the cracks between rocks and on some of the surfaces back around Erebus, and earlier between the rocks around Burns Cliff.

Markg, you ask a very interesting question about the size and speed of the Concepcion impactor. My overwhelming impression -- just from a visual read -- is that it was small and (very) fast as opposed to larger and slower. The rays in particular make one feel this way -- a slower impact would seem to be associated with a more symmetrical, concentric detritus pattern, as the energy has more time to become evenly distributed. But IANAP (I am not a physicist).

Ant and James, astounding -- absolutely astounding -- panoramas!

Another thought regarding this currently emerging panorama, and one that might be of particular interest to those involved in space journalism:

The Rover mission planners have always been concerned to capture scenic vistas; but as the mission has gone on, they have become better at it (having missed, I think, an early opportunity to get a full panorama of the mid-distance Endurance crater) -- and it seems to have become more of a goal in and of itself.

Witness the careful positioning for the current panorama -- I will not say of Concepcion, but with Concepcion as its focal point -- with the rays of detritus pointing to the mountains (or whatever they are) on the horizon; a framing, one might say, that goes beyond the needs of pure science.

Of course, one could argue that the most scenic shot is also going to be the best for science; but particularly in this case, it would seem the time devoted to the the panorama goes beyond what is needed for a scientific overview of the site, some of which time might be better spent -- from a purely scientific standpoint -- in taking detailed photos of the many interesting pieces of ejecta.

Consider also the Cassini mission -- little effort is made to hide the fact that part of the goal is simply to get some stunning photos.

The point being that -- in addition to science -- the care and feeding of the human imagination is becoming an accepted part of these missions.

And I am sure this same point has been made at other times on UMSF -- but Concepcion seems to be an especially telling example.