I hope this doesn't lead to another "battle"...it's old so hopefully not. As long as it's being brought up again though, I have a question. Idea? Question.
Something.
It's not likely a meteorite, but that doesn't limit it from falling from the sky. Could falling from a satellite or uber-high altitude airplane cause a lump of aluminum to get hot enough to flow? Or a blow torch? Or somehow get it warm/hot enough and use fast moving air from...(something pressurized maybe, or a wind tunnel) to create the effect of flow?
Would that explain the long, drawn out tear drop shape, flaky edges, and ring like structure in the cross section?
I'm not a metalurgist, but looking at this reminded me of...oh gosh, I think it was in
"Deception Point" by Dale Brown. The story was a meteorite was found that turned out to have fossils in it. The people investigating discovered it was a fraud--it was a terrestrial fossil in a rock that had been treated with a blow torch of sorts to make it LOOK like a meteor and placed under the ice where it could be found by the new government satellite.
Anyway. Just a question as I really no nothing about aluminum beyond what's been explained in this thread already. I have no proof or means of replicating any process that could lead to these results. A thought experiment if you will. A hypothetical question.
Edit: Upon second thought I should add the disclaimer that yes, I know Deception Point is fiction but the idea stuck out to me as one that isn't tooooo far out. Ok. Now I'm done!