Comment Re:Precident has been set (Score 1) 213
Barringer Crater was a pre-existing landform that wasn't even confirmed to be of extraterrestrial origin until Shoemaker's 1960-ish PhD thesis. Granted, there was suspicion that it was from a meteorite impact, but the theories up until Shoemaker's were all incorrect.
Come again? The theory that it was a meteor impact was actually incorrect until Shoemaker found high-pressure quartz polymorphs? The preponderance of evidence supported it being a meteor impact decades before that, there were no other plausible explanations for the formation that fit the evidence. The discovery of the polymorphs coesite and stishovite provided a unique unambiguous indicator, but in no way was required to demonstrate that the meteor crater explanation was correct. The real significance of the polymorph discovery was to provide reliable indicators for other formations of uncertain origin. The original Shoemaker paper (Science, Vol. 132, p. 220, 1960) makes no claim that it "proved" that Meteor Crater was a meteor crater, the paper assumes that as a known fact.