# Meteorite question

**URL:** <https://boards.straightdope.com/t/meteorite-question/474031>\
**Category:** Factual Questions\
**Created:** [November 22, 2008, 9:01pm UTC](https://boards.straightdope.com/t/meteorite-question/474031 "2008-11-22T21:01:26Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![detop](https://avatars.discourse-cdn.com/v4/letter/d/bcef8e/32.png) [@detop](https://boards.straightdope.com/u/detop)\
**Post date:** [November 22, 2008, 9:01pm UTC](https://boards.straightdope.com/t/meteorite-question/474031/1 "2008-11-22T21:01:26Z")

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Follo0wing the impact of a meteorite in Alberta this week ([see this thread](http://boards.straightdope.com/sdmb/showthread.php?t=493990)).

I consulted the [Earth Impact Data Base](http://www.unb.ca/passc/ImpactDatabase/index.html). And one thing that I noticed, there seems to be more impacts in the northern part of the northern hemisphere (Quebec, Finland Sweden). Is it just because these areas are more well-known or is there another reason ?

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**Author:** ![Inigo\_Montoya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inigo_montoya/32/124_2.png) [@Inigo\_Montoya](https://boards.straightdope.com/u/Inigo_Montoya)\
**Post date:** [November 22, 2008, 9:08pm UTC](https://boards.straightdope.com/t/meteorite-question/474031/2 "2008-11-22T21:08:24Z")

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With about 70% of the world’s land mass, the Northern Hemisphere presents a better target. Prolly a lot of space rocks lying around on the ocean floor down under.

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**Author:** ![Inigo\_Montoya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inigo_montoya/32/124_2.png) [@Inigo\_Montoya](https://boards.straightdope.com/u/Inigo_Montoya)\
**Post date:** [November 22, 2008, 9:15pm UTC](https://boards.straightdope.com/t/meteorite-question/474031/3 "2008-11-22T21:15:25Z")

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Misread the question. No insight into why they would concentrate up north.

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**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\
**Post date:** [November 22, 2008, 10:03pm UTC](https://boards.straightdope.com/t/meteorite-question/474031/4 "2008-11-22T22:03:07Z")

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My guess would be that, for whatever reason, some countries participate in supplying the database, and some don’t. If you look at North America, for example, nothing from Mexico.

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**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\
**Post date:** [November 22, 2008, 10:22pm UTC](https://boards.straightdope.com/t/meteorite-question/474031/5 "2008-11-22T22:22:30Z")

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The other point, besides the fact that the Northern Hemisphere has more land than the Southern, is that impact craters are concentrated on _shields_ – parts of the continents that are geologically stable and very old, even in geologic terms. The Canadian Shield has either a majority or a substantial plurality of all known definite impact craters. The Scandinavian and Angara (in Siberia) shields also have a bunch.

The Vredevoort astrobleme, one of the largest, is located in South Africa, but on the shield there (Karroo? I don’t recall the shield name).

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**Author:** ![detop](https://avatars.discourse-cdn.com/v4/letter/d/bcef8e/32.png) [@detop](https://boards.straightdope.com/u/detop)\
**Post date:** [November 22, 2008, 10:32pm UTC](https://boards.straightdope.com/t/meteorite-question/474031/6 "2008-11-22T22:32:28Z")

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Thanks, **Poly** , that would probably explain it.