HiRISE has seen concentric forms in craters before, like ESP_018522_2270,, or PSP_003398_1910. However, the one present in this image seems like a very good candidate for a serendipitous second impact right in the middle of a pre-existing crater.
Unlike the forms in ESP_018522_2270, it appears here that the small crater in the center of the image has thrown out ejecta, including some boulders. Additionally, the one kilometer (a little over half a mile) central crater looks fresher (and therefore more recent) than the larger (7 kilometer, or not quite 4.5 mile) crater, which is heavily eroded. The smaller feature also appears to have a raised rim, as would be expected for an impact crater, but not for a central pit produced by a single impact into a layered target. Although newer craters are frequently found inside older craters, this sort of bull's-eye second impact is rare.
The subimage shows the rim of the central crater at full resolution. In this image, you can see boulders on the outside of the rim that are likely ejecta. Also visible are boulder tracks on the crater wall, formed as blocks on the rim tumbled down the slope.
Written by: Nicole Baugh
Original release: 29 November 2010
The centering of the the second impact is that accurate, it seems magic. Didn`t we hear about another magic bullet some decades ago, involved in the very public killing of .... . Two magic bullets make a series. Probably there are some others to follow. Ok osd, stop to sound sarcastic.
The centered crater is the younger one, right , and some ejecta is still visible around. Besides the amazing centering of the daughter crater, - where are the remains of the impacting masses ? Regarding the diameter of some martian craters, there have to arrive some really huge chunks bombarding mars. It seems they leave no traces on the surface. Another proof of magic on planet Mars ? (Can `t stop it. )
Is this what you mean by a composite? If so, it does not look much like this, but I am not a geologist or whatever the scientists are called (vulcanologist?).
Scientists just have to offer some explanation to explain it away. It maintains their authority.
If he or his position did not make a comment on this, then we would not believe what he (or his position) says in the future.
It is important that we belive these explanations for us to believe future explanations and dont forget - familiarity breeds authority in our minds. All part of the game to get the masses to accept what the scientists tell them, however much it is opposed by our common sense.
Turning this thing on its head, what if these 2 and 3 co-joined craters were created by something under the ground instead? That would mean asking .... what could possibly cause that? .....Who, when, how, and all these other questions which arise if there is no pat explanation from a scientist.
Always think for yourself and examine what others say (even authorititive sources) in the light of your own experience and common sense.
„If you equip an infinite number of monkeys with an infinite number of typewriters, one of them will write all of Shakespeares sonnetes without any mistake certainly“, but an infinite number of monkeys will fail to do so.
„ Occam's razor (or Ockham's razor[1]), often expressed in Latin as the lex parsimoniae, translating to law of parsimony, law of economy or law of succinctness, is a principle that generally recommends selecting the competing hypothesis that makes the fewest new assumptions, when the hypotheses are equal in other respects.[2] For instance, they must both sufficiently explain available data in the first place.
The principle is often incorrectly summarized as "the simplest explanation is most likely the correct one". This summary is misleading, however, since the principle is actually focused on shifting the burden of proof in discussions.[3] That is, the Razor is a principle that suggests we should tend towards simpler theories (see justifications section below) until we can trade some simplicity for increased explanatory power. Contrary to the popular summary, the simplest available theory is sometimes a less accurate explanation. … . „
This image shows a remarkable double crater with a shared rim and North-South trending ejecta deposits. These two craters must have formed simultaneously.
The bolide may have consisted of two objects of the same mass that were loosely connected, perhaps similar to comet 103P/Hartley 2, which the Deep Impact spacecraft (EPOXI mission)encountered on 4 November 2010 (see here). Many more asteroids than comets impact Mars, but asteroids also come in double shapes, like asteroid Itokawa explored by the Japanese Huyabusa mission. The bolide must have separated into two distinct pieces prior to impact in order for two craters to be recognizable.
Written by: Alfred McEwen
Original release: 9 February 2011
In my opinion.....
It is assumed by Mr. Mc Ewen, the double crater was caused by two pieces from an once solide object, that has broken into two pieces. These two pieces must be of comparable masses , in regarding the nearly identical depth and the nearly perfect identical shape of the „impact“ craters. Besides the unlikelyhood of such a clean separation, this would have to have happenend inside of the martian atmosphere `cause both impacts are that close together. Okay, the martian atmosphere is supposed to be very thin, so it would not show that much influence on entry speed / velocity, means the separation could have happened already in great altitude or even outside in space.
The chance this happened outside of the atmosphere would imply a really chirugical separation into two eqivalent masses too and it is more unlikely, cause it eliminates the slightest disturbing and influencing force working on the two bodies all the long way down, which would have changed the inflight orbit significantly over the flight distance till touch down.
It seems more plausible the body separated into two parts shortly before the impact. Why hasn`t it broken into three, four five , six parts ? Smaller and bigger ones ? Taking into consideration the forces causing, participating in and influencing such a separation process during full flight speed, this would have been more likely. Okay we do not know the real composition and the true nature of the impacting body and of the socalled „impact“.
Anyway, to separate a probably inhomogen body into two separate bodies of exactly the same mass assumes a procedure using some really fine ( and big ) specific gravity scales and a really big saw at work.
What gives me the creeps is the borderline between the two craters and the perfection of the shape of the shared rim. The perfection of the borderrim together with the perfection of the two „ejection flags“ and the close local distance of the two impacts suggest that two bodies of equavilant mass, and of same orbit velocity hitted the ground simultaneously in the very same millisecond.
See the recent caption titled "Conjoined Twins" (ESP_020894_1395). This is another example of simultaneous impacts, but this time producing three conjoined craters!
Written by: Alfred McEwen Original release: 23 February 2011
Comparable ? Maybe.
But what comes into mind at once is, that it looks older and more weathered. How has it looked in its fresh state ? Similar to the Conjoined Twins ? Hard to say so. Lets assume it looked like the Conjoined Twins.....
Using a Triple Event as a reference sample to support the creation theory of a Double Event, without mentioning the questions and problems, does not solve the problem of „unlikelyhood“ and backing up the „two body theory “ with a „three body theory“ makes a simple explanation even more unlikely, cause the „three body theory“ depends on even more variables needed.