Just what effect it has on the topography I don’t know precisely, but it may create a rill or a ridge, if the compression force was large enough. But would, could, it happen really? I would have thought the effect would have been continuous anyway, not unlike any other effect we see in a fluid, including in the atmosphere. The classic is the cork bobbing in the ocean, as a wave passes by. It is influenced only by the transfer of the energy of the wave through the water, essentially moving in a vertical circle and resting where it was before.

We’ve all seen the high speed imaging of the effects of that shockwave in the tests of Nuclear explosions even fifty or sixty years ago, destroying buildings and severely flexing trees and the like. I think somehow similar effects on relatively loose ground features such as sand, rocks and soil will be re-distributed by the initial wavefront, but when the effect is effectively cancelled out in the meeting of the two wavefronts, the debris just falls to the surface in a line reminiscent of the straight line boundary. And a valley represents the point of rarefaction in that wavefront where debris falls at the compression point on each side of that lower pressure point. That it ends up being a straight line is a representation of those colliding wavefronts and forms a valley.

Ivan.

We see Earth is afflicted. We’ll have to do something about that soon.

1. the blast structure seems to indicate the Left hand blastwave was larger, notice the trough gouge is more pronounced. This also indicate that the center rock might have been the largest (as if that matters).

2. In side to left upper quadrant is a small double crater of the same only newer impact paramiters. Double crater Straight center Wall. Now that is lightning striking in the same place!

Enjoy

Capt Tommy

Shouldn’t it be:- KaBLAM3 (that is, …Cubed. Or at least X3 (…times three)! (I couldn’t make a proper superscript 3 – could not find any way to address the fonts, they are apparently not available in the comment box. I could be wrong, anyone know better?

Ivan.

Srsly, atmospheric breakup isn’t the most plausible mechanism, is it? Shoemaker-Levy was a pretty neat demonstration of tidal disruption and crater chains (well, mushroom-cloud chains, in this case)…

Something similar – although with more widely dispersed fragments – has probably happened on Earth before – see : [link snipped]
Manicougan crater …

Hmmm… Actually, come to think of it :

http://en.wikipedia.org/wiki/Clearwater_Lakes

is more like the one I was thinking of with that.

That’s one – no, *two* – impressive Candian craters!

Except….. what I had resolved to be the two straight, almost parallel “valleys”, are now slight ridges. And I am now at a loss to explain exactly why.

Anybody offer any explanation? I cannot find or remember seeing any examples for that on Earth.

And as Filipe @44 above says, the total impact was a giant evil peanut, it would have to have been a three kernel peanut! Having grown peanuts, I know they do exist, like double-yolk eggs, rarish but existing in nature. In space there has to be rarities too, but explaining the mechanics is another thing.

Ivan.

Those are some amazing craters.

As for the impact itself, I feel it was a direct hit, straight in, vertical. (It does happen). This would account for the lack of oval shaped craters. Each piece, roughly the same size, and just happening to be in a triple dead-heat in the race to the planet Mars, impact in line at the same moment. The geometry of the shock waves would create a straight (-ish) line at their own impact in the atmosphere. Consider each of those shock wave as a sphere, then the result would be essentially cancelled out, except at the surface where massive movement of matter would be affected, probably causing a straight valley, one on each side of the central crater.

There seems to be some slight asymmetry as the two valleys or whatever, are not parallel – an indication of a dynamic event, and not an artifact of something else? Is there any evidence that there may have been a slightly earlier impact of a fourth piece, but obliterated by the craters that we can see? In that case, what would be different? I suppose the ripples we see are the normal dune structure where loose sand is being blown around by the prevailing winds, and not interference patterns that we see in holograms, and Moire patterns, firmly etched in the solid rock.

Arrrr, wish I hadn’t mentioned dune…. must have been the Spice… sorry, but some others beat me to it, and I couldn’t help myself!

Ivan.

PS. Looking at that image again, I definitely see the lower left crater as concave, but the lower right is convex. The long valleys are both concave but the central big crater won’t budge from being convex, though there seems to be some dished look to some of the central parts of the three craters. Maybe there IS a big mound at the bottom part of the crater wall area . I can see both effects at the same time, which seems to be an improbability.

Ivan

I don’t think impacts of this size would have been catastrophic, except in very particular cases. The reason I think that is that these objects would have been much smaller than the rock which hit the Earth at the end of the Cretaceous Period and formed the Chicxulub crater. That rock was probably responsible for the death of large portions of the Earth’s ecosystem, but it certainly wasn’t enough to wipe out life on Earth. Note also that it was the more complex life which suffered most in that impact.

So I think those impactors could only have been responsible for wiping out life on Mars if the only life on Mars had been directly under those rocks when they struck.

“I’d appreciate your informed view on my uninformed guesswork!”

Sorry, but my comments above were little more than uninformed guesswork too.

Air does NOT transmit all impact energy, and in fact it isn’t even required.

@Phil:Looking at the Report published in Chicago Chronicle,”Rowley said that the chance that these craters are randomly so aligned is near zero.” The same question comes to mind also.If the meteor breaks at the atmosphere how come they all fall just beside each other.Seemed like all the three meteors might have come down just side by side or has broken off just after touching ground zero.
Report:http://chronicle.uchicago.edu/980319/craters.shtml
Also if we look closely in the enlarged image of the impact zone,I find some zig zag lines,what could be the reason for that.Also the sides of the crater seems to have eroded at some places and smooth at other places…