I'm ready with another Christmas gift idea for your favorite MatSciWit blogger.
Today's article looks at the evidence for a meteorite impact in Libya creating temperatures high enough to fuse sand into glass. The scientists were trying "to nut out" (their phrase, seriously, check the article) whether the meteorite actually impacted the Earth's surface (leaving a crater that hasn't ever been found) or whether an airburst could have released enough energy to fuse the silica into glass.
The researchers looked for mineral evidence of meteorite impacts - zirconia and reidite. The 'smoking gun' (again, their phrase) would have been reidite, but they found no reidite - because it resrcytalizes into zircon if given time and cooling.
What they did find, however, when looking at "the crystal orientation of tiny interlocking grains of recystalized zircon" was that the orentiations showed evidence of former deformation from impact - something that could not have been created by an airburst.
That's what they say.
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