We have now seen several craters on this side of Mars in various stages of erosion. This one certainly seems
to look like one of the younger ones. Does anyone here have a sense of how old this crater is? Are we still talking in the millions of years old or is this much younger than that? From orbit we can get a general sense of the age of land masses by doing a crater count. Now that we have visited a few craters on the ground, can these be compared to other craters form orbit to get a rough idea of age?

It is hard for me to imagine that there would not be. Even if the surrounding ripples have never migrated over the crater there should be an accumulation of dust similar to what was seen in all the craters so far. We can see some small ripples on the inside edge of the rim that is visible from here, so there should be more at the bottom.

Phil, I love the way you always step up to the plate with the polar version. It's the one thing I make a mess of when I try it myself. Now that I think of it, have you done a polar version of the "barbecue" we had over at home plate?

Hmmm, I didn't think of that. Do you think it would be desirable? Someone might fall off.

Phil

Now, that's thinking outside of the box. Now, I am wondering how it would appear.

I picked up my geologic education on-the-fly, so I could understand what was going on in re the Apollo expeditions to the Moon. I wanted to understand what the Moon was made of, and how it came to be, and found that I needed something of an education in geology to do so. So, I read a lot of books and came out of it with a pretty decent understanding of the basics. (Because I'm self-taught, though, I do have gaps in my knowledge, and I appreciate y'all's patience when I ask to be filled in on some point I had missed.)

-the other Doug

It looks like a masonry crater to me -- laid fieldstone made in the shape of a crater.

The smooth interior sort of floors me (pardon the pun). This evaporite is one of the most erodable materials we've seen anywhere, it erodes down to smooth, flat paving stones quite easily. The interior surface and rim crest all appear to be made of evaporite blocks which have been eroded smooth, but the ejecta apron around Beagle retains blocks of the stuff that are still almost craggy. I'm also taken aback at how the evaporite blocks and the darker "matrix" into which the blocks are set seem to have been sculpted as a piece, and do not appear to have eroded at differing rates. That darker matrix must have friability similar to the evaporite.

It also appears that the Beagle impact occurred into a substrate that was already substantially jumbled by the Victoria impact. In other words, Beagle exhumes the highly shocked and jumbled Victoria ejecta. Which would imply that the Victoria ejecta blanket is fairly deep, here -- at least as deep as Beagle -- and that it underlies the etched terrain immediately surrounding the currently-visible ejecta apron. I'd have to think that if Beagle impacted into a substrate that retained stratigraphic layering, we wouldn't be seeing such a jumble of fieldstone-like blocks making up the raised rim. We'd be seeing something that looked more like Eagle or Endurance.

I wonder if the dynamics of the impact exhumed the ejecta blanket and, as the fireball expanded from the impact point, then smoothed the very friable evaporite into the very smooth walls we observe? That would mean that the interior of Beagle was never rocky, was smooth from the very start. Which could mean it's a quite young crater, indeed.

-the other Doug

Well, in the overhead MOC image, the floor of Beagle appears dark. That's rather common in MOC overhead images of craters, and often doesn't translate to anything like the same albedo difference when seen from the surface. But it usually does suggest a dust fill in the bottom of the crater. And on Mars, when a crater has some dust fill, it usually displays drift/ripple morphologies.

However, since this is a relatively young crater, there is also the possibility that it started out with a blocky floor. If it's young enough that there is still a decent block population on the floor, then the dust fill might be in an aerodynamically complex position in which only very small ripples, and not a coherent ripple field, would be created.

It will be interesting to see exactly what lies in the bottom of this hole...

-the other Doug

It was long, it was painful, I violated poor Horton's beautiful anaglyph to get the red and blue somewhat balanced...

...But finally, Gimp gave me a flicker animation. It is scaled down to fit under the 1MB limit.

Click to view attachment

dvandorn: It will, indeed. But not just how it appears at the bottom, but also how the whole picture comes together. I'd like to learn if the regional ripple field predates or postdates this crater's formation.

The smooth interior floors me as well. I thought that was supposed to be caused by the slumping of a later overlying layer; as described in the Edgett paper, as I understand it. That doesn't work with a young crater. As you've pointed out, it really seems at odds with the appearance of the ejecta blocks lying about.

Not such an exemple was found back on landing site. Any relation to Fram/Endurance ? I mean, Fram was quite a mess as compared to Eagle.

oDoug--

Yes, the flagstone crater interior contrasting with the minespoil exterior is distressing to me, also. I'd expected the interior to be cleaned out by the "explosion of the impact", but it has a "sinkhole" appearance with neatly-fitted paving slabs. Of course, we've only seen a small part of the interior so we may be jumping conclusions, but this first look says "strange". I'm seeing two broad type of rocks on the ejecta blanket: light- and dark-toned in L2. The first look into Beagle will be an eye-opener; it may be jumbled because that is the nature of the surface here.

The ripples we see appear to be sandy in the Pancam views thus far; I don't sense Blueberries in thse first views.

--Bill

Well, Climber -- Endurance and Eagle are old enough that their ejecta blankets have been worn down to a flat surface. That doesn't resemble what we see here at Beagle. Fram is a classic small, blocky crater -- it has blocks in the ejecta blanket and also in its inner walls. And Fram is a lot smaller than Beagle. So, even though it's rather a mess, the Fram impact probably wasn't energetic enough to blow a clean hole into the substrate, as Beagle has done. Fram's a mess because its impactor only had enough energy to blast a few rocks around, not to dig very deeply into the target rock.

Beagle seems to exhume a substrate that is made up of a megabreccia-like layer of evaporite within a basaltic sand matrix. In other words, a lot of jumbled rocks contained in hardened sand. Which is what Victoria's outer impact splash ought to have looked like. That's what leads me to think that the Beagle impact has simply exhumed a badly jumbled mess of Victoria ejecta.

-the other Doug

Yeah, Bill, I noticed the lack of blueberries, too. Speaks for this layer of evaporite having a different history from that back along our route -- it never sat and soaked in the same type of water that the evaporite which developed the hematite concretions was soaked in.

Whether this means that the mineral content of the water that soaked this evaporite was different, or that this evaporite was never re-soaked with the amount of groundwater (or standing water) needed to form the concretions, it's impossible to say. But I'd say it's a good bet that one of these two situations is responsible for the lack of blueberries.

Did we see blueberries in the Payson ridges at Erebus? I can't recall, offhand. I'm trying to get a feel for the blueberry distribution around older vs. younger craters, and in (presently) higher vs. lower topography. I know it's dangerous to try and evaluate ancient water levels based on current topography, since volcanic and tectonic forces have warped the crust all over Mars since the times when this land was covered with water. But the blueberry record *does* tell us something about how the water was distributed across our path, I think...

-the other Doug

really quite a miniature golf wonderland here... far more than i expected.

Looks like a weekend stop over - FHAZ obs of the IDD today - IDD MI work tomorrow

Doug

Having great fun reading my new geology dictionary... lots of "Aaah! NOW I understand why they were so excited!" lightbulbs lighting up above my head as I flick the pages... vugs, festoons, cross-bedding, it's a whole new world!

Thanks to everyone for their suggested links to geology dictionary websites. I appreciate you taking the time to send me those, and looking at the latest pics from Oppy at the geological theme park that is Beagle Crater I can see I'm going to be visiting those sites and thumbing through my book a lot. Even before I started reading up I thought "Hmmm, that looks like a huge piece of breccia..." when I saw the first detailed shots of Beagle's farside, what with all the blocks set into the wall. I knew about breccia because I'm a very modest meteorite collector, and that requires some knowledge of the interiors of rocks etc, and looking at the Exploratorium pics I was specifically reminded of one of my most loved meteorite-related rock specimens, a small, 3"x3" polished piece of the famous "Alamo Breccia" which, the label here tells me, dates back 367M years to the Late Devonian period... beautiful ...

Also learned a lot from that one brilliant episode of FROM THE EARTH TO THE MOON where the Apollo crews are taken out into the desert to learn field geology from Jack Schmidt's old professor (I'm sure you know it... the one that prepared Dave Scott for his mission, and showed him looking out of the top of the lunar module, surveying his surroundings and describing what he could see to the geologists listening back on Earth...stunning stuff!) , that made a huge impression on me, and left me wanting to learn a lot more about rocks and the history of the Earth.

Now, and I still find this amazing, I'm looking at images of rocks on a different planet and, thanks to people on here, am able to make sense out of what I'm seeing, so thanks.

Quick question for anyone with time to indulge an enthusiast here... can anyone yet identify any shattercone candidates around Beagle? And while I'm here, is anyone else intrigued by this rock and its layering?

Thanks hendric for the flicker animation I found it looked best for me from about 4 feet from the screen.
And a few general comments as I havn't posted for a while, Beagle looks great can't wait to see inside and close-up.
Mystery man is very helpful what size shoes does he wear? he often stands near rocks that are about the same size as his feet,so the rocks are about a foot long I guess.
Is there a site where they display mini-TES plots overlaid on the photographs like they did at Eagle crater with Haematite in red and basalt in blue etc?
Roy F

Cool, thanks! And thank you Horton for allowing your anaglyph to be violated.

Brian

For those of you who don't check the jpl site for images, the full 360 degrees of navcams are in for sol 891. Seems exploratorium is a bit behind.

Wow, that was a good drive - "Jesse Chisholm" is barely visible now (well, I guess the Navcam image compression has something to do with that), and we seem to be north and a little east of "East Hillock". I've updated the Quicktime VR for this site with the 360 degree Navcam view.

When I saw that there was a drive from Jesse I thought "OK - it's going to be either a short drive for new IDD work, or just a beauty across that outcrop to close to Beagle..."

And then when the images came down I went "Ahhh - leadfoot it was then "

Doug

Here is a navcam anaglyph of the 360 degree sol 891 panorama.

You're correct, oDoug. For some reason I was thinking that Beagle was created in undisturbed evaporite (ie, neatly stratified) and I was having trouble visualizing how the appearance of the crater interior came to be. But as you say, Beagle "seems to exhume a substrate that is made up of a megabreccia-like layer of evaporite within a basaltic sand matrix. In other words, a lot of jumbled rocks contained in hardened sand. Which is what Victoria's outer impact splash ought to have looked like". I was on the lookout for that, but decided somehow that we had flat, layered rocks here.

--Bill

Well, let's wait a minute. I've seen some blocks that might support such a view, but there seem to be many more others that display a nicely intact and mostly undisturbed previous history. The darn thing is pretty jumbled up though, isn't it. It's a mess, and although it has some similarities in common with Endurance. I am not ready to claim I understand what has happened here.

I do like what I see in the latest update:

"Over the past 50 sols the team noticed a gradual cleaning of the solar panels similar to a more-sudden cleaning event experienced one Mars-year ago in "Endurance Crater." Removal of some of the accumulated dust on the panels allows greater production of electricity from sunlight. Opportunity's solar panels are now producing just over 500 watt-hours per sol."

...and they expect Spirit down to 275 by August 8th
Regarding Oppy, I suggest two possibilities :
1- There's an effect due to the proximity of Victoria. I still think that the "relative flatness" of the apron is due to winds accelaration (Ventuty's effect?) when winds enter and leave Victoria, and Oppy is close enough to be feel the wind.
2- Well, just by chance!
Even without explanation, it's good news

A small thought on the floor of Beagle crater, since it had be befuddled also.
Could it be that there have been a crater here that eroded so much that we no longer see the original crater but one imprint of it in the soft meridianian rock here.

Following this thought it might be one explanation as why we have a hard time seeing any raised rim on Victoria of the type we've been used to see in for example the moon craters, so that the rim might have been eroded away also over the eons.

Hi

Here is two panorama of Beagle Crater.

This one is an anaglyph :



This other pic is a simple pano (for thos who have not 3D glasses).



Click on the pictures to have the hires

I'm not sure I understand what has happened here either. I'm rather like Dave Bowman when he exclaimed "my God, it's full of stars". I've been on the lookout for areas on the etched terrain that look disturbed (they look "jumbled"), but many more areas do look undisturbed in that there is that neat and tidy paving-stone appearance.

The exposed evaporite on the approach to Beagle looks undisturbed but the initial views into Beagle and presumably the shallow subsurface look quite disturbed. But Beagle is a fresh crater, possibly the newest one we've seen here and it's ejecta blanket looks as expected.

--Bill

So, how about this for an idea. During the Beagle impact, the evaporite layer that we see now was buried pretty deeply in sand. The impact mostly overturned the sand layer, and the evaporite was heavily shocked but stayed mostly in place.

Michael

How's this notion for an explanation of the contrast between relatively smooth floored interior and blocky exterior. Assume the surface was water saturated and frozen at the time of impact, but the heat of the impact was sufficient to melt the interior enough to allow everything to settle and smooth out, while the blocks tossed further away landed upon a surface which stayed frozen and intact. Later the ice sublimed away.

A full polar pan from sol 891. Here I have taken one channel (red, I think it was) from CosmicRocker's anaglyph (thanks!) - and reprojected it.

Phil

Click to view attachment

One curious statement in the latest oppy update:

I assume they meant "... to determine a path to Victoria"

No - Beagle - that was the next drive.

Doug

I think what fredk is saying is that the Pancam image of "Sandsheet" was toward Victoria, not Beagle - which it was. Also, it was to the southeast, not to the 'south' strictly speaking. The report seems to be in error.

Edit: Unless of course they really were planning on going that way to Beagle... in that case, they were simply out of their minds.

That's exactly what I was saying, Mhoward!

I forgive the report writers for "south", and interpret it as "southish".

The report is interesting, as I should have elaborated, since it gives us our first official indication of a potential approach route to Victoria. Recall that there was only a single "sand sheet" pancam image, which defines an approach direction well. It points pretty much towards the northwest corner of Victoria, ie the closest corner to us, not surprizingly!

The crater Epsilon is in that field of view as well, I believe, and I think that would be an obvious intermediate destination to fix our location, since if we just drove to some point of the near rim of VC we'd probably have a heck of a time locating ourselves.

A colorized navcam panorama of Beagle:



Although I did use a (saturation enhanced)
palette of colors derived from calibrated pancam images ...
I'm afraid that the first calibrated
multi-filter pancam composites of beagle will prove the colors of this one wrong ...

<usual color diclaimer>
so take this just as my own "impressionist best color guess" view of the scene without any warranty
</usual color disclaimer>

A quick stitch, since no one else has done it yet:

Nice Pan! The terrain approaching "Beagle" is really interesting.... almost looks like a different planet!
(No pun intended). Should be quite a view when Oppy pops up on the rim. - SB

My version.



James

They are both gorgeous in their own rights, and nods to Nirgal for the colorized nav version. As much as I love the detail in the pancams, there is something special about the colorized wide-angle view.

Paultry in comparison to the work of the masters, but perhaps of interest to some, here is a very narrow-angled view of the latest bedrock brushing/grinding.Click to view attachment

now that the L2567 color pancams are available I used them to re-calibrate my
navcam panorama colorization to the following (hopefully) more realistic one:

My first thought at seeing the two blueberries close together was of a cell splitting into two.

The blueberries probably have a chemical origin, but part of me can't help but wonder if they have a biological origin.

And my version



After, I've made a desktop wallpaper :



Nirgal, your Alien Lanscapes are very nice

Question for all:

1. How long should we stay at Beagle or Corner Crater and investigate it before we head to Victoria?

2. What rocks from what we see in the images do you think would be interesting targets?

3. Should we drive into Beagle?

4. I wonder if Woodstock is hiding in Beagle (Snoopy) crater <--- Looks like a birds nest???

2. The flat stones from the bottom to the top (about 1.5 meter) which have straits lines. These are of interest to be investigated.
3. Yes, inside Beagle crater is interesting. I have already spoted that BC has strips of some kind of sedimentation or stratification that might by caused by the water or sand depositions.

Rodolfo

Drive into Beagle Crater? I don't think anything around here is worth risking Victoria for.

That's what I thought. Maybe toddle up to the rim and have a look-see, then high-tail it to Victoria while the rover is still healthy. If there's no approach path into Victoria, then come back and play in the rubble pile.

Maybe get up onto one of the high spots and use the pancam to have a look at the ejecta blanket from Victoria, see what it might offer.