As scientists debate what killed off the dinosaurs, the question (as to where the meteor that caused it landed) revolves arounf the Yucatan region of mexico. However, has anyone considered Hudson’s bay? Two things might be relevant"
Does a meteorite have to hit the Earth at a 90 degree angle to get a circular impact crater? How come we don’t see many pear-shaped ones, or long gouges?
Things approaching the atmosphere at an angle often “bounce”. Plus, the greater the entry angle, the more heat will build up around the object, so the smaller it will be by the time it hits the ground (if at all).
And long*, too.
*If measured in penile inches.
I’d always thought of Hudson Bay as square.
Recognising that I’m at the arse end of the planet, and that for some inexplicable reason, Hudson Bay tends not to loom large in my daily affairs, I thought that maybe my memory was faulty, so I had a look at the globe that sits on my computer desk. Hudson Bay looks a little rounder than I remembered, but it still seems closer to a square than a circle.
Most impacts produce circular craters unless the impact is at a very shallow angle. From this page (talking about some elliptical geological structures that are not craters but is the first cite I found).
>Does a meteorite have to hit the Earth at a 90 degree angle to get a circular impact crater?
The movies get it wrong. It’s not a big rotating ball with diesel flames billowing behind it, and you wouldn’t see it move. It’s more of a lightning bolt, an absolutely straight line that happens all at once and doesn’t have any direction to it. The meteorite burrows under ground and slows to a stop. However, there is a great deal of heat involved, and the matter closest at hand is vaporized, and the vapor blows a crater open. The same thing happens on smaller scales with shallow buried explosives. I’m not aware that much of anything provides a clue, after the fact, about which direction it came from (unless perhaps there is a line of air blast damage or radiation burns from the lightning bolt).
As a bit of trivia, cars and pedestrians generally have a smaller mutual speed ratio than big meteorites (at ground level) and bullets.
In the southeast USA, there are many oval or roughly teardrop-shaped depressions called Carolina Bays which, some theorists say, could have been caused by meteoric showers but there is little or no extraterrestrial material in them (they could have been formed by glancing, or skipalong hits, IMHO). see the “Theories of Origins” section about halfway down in
Besides the Carolina Bays, there are long trench-like “gouges” in Campo del Cielo Argentina that, it was suggested, were due to glancing meteorite strikes.
http://www.youtube.com/watch?v=hlfDVNX8KBk
When I looked these up, I found this article suggesting that, although they started as meteor craters, a lot of the shape may be due to weathering. No pix, whixh is a shame – they look impressive:
http://news.nationalgeographic.com/news/2002/05/0509_020509_glassmeteorite.html
The link I gave above (post 8) is specifically about the Carolina Bays and the author of the link discounts the possibility that they are craters.
((Anecdote: I used to live in South Carolina about a quarter mile from one of the bays. It’s pretty much filled in now (they built a shopping center in it) but the local story was that it was a meteor crater.))