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I was reading this article about the Nov 2015 Fireball surge. One explanation was that "... gravitational forces from Jupiter causes the Taurid meteor stream to be more heavily concentrated near Earth at certain intervals".

So I got curious of about the statistics of meteorite falls per month. As defined, these are meteorites collected after their fall from space was observed. For the years 1600-2012, there have been about 1100 confirmed cases all over the world. The ones where the month is also known (more than 1050) is charted below:

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Questions:

  1. With 1-12 as the months, is there an astronomical reason why there should be more meteorite falls (107 cases) starting April? (The Lyrids?)
  2. Or is it just a sociological reason, meaning it is after winter, and more people are outdoors to observe possible falls? (But then again, the contribution of cases from the Southern Hemisphere, where the seasons are reversed, should even it out.)

Edit: As pointed out by J. Custer in the remarks, the contribution of the Southern hemisphere is relatively meager:

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  • $\begingroup$ For #2, consider that many (many!) more people live in the Northern Hemisphere than the Southern. All of the US, India, China, Europe, parts of Indonesia, all of Central America and parts of South America, and Africa north of the Congo... $\endgroup$ – Jon Custer Apr 13 '16 at 21:14
  • $\begingroup$ @JonCuster: Yes, that occurred to me. One way to test #2 would be to break up the dataset into two parts, northern and southern hemispheres. If the trend still persists, then its #1. But it's hard to segregate the more than a thousand data points properly. Unless someone here is savvy with manipulating these things. $\endgroup$ – Tito Piezas III Apr 13 '16 at 21:29
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I don't know the exact distribution of meteorites, but something similar to #1 is possible.

If we consider the case that some fraction of meteorites come from a broken up comet or asteroid, many of the pieces will remain near the original solar orbit. The earth will be much closer to that orbit during a particular month, year after year.

While random meteorites (like those from Lunar or Martian impacts) would be expected to have a nearly random distribution, a subset might be strongly correlated to particular times of the year. Although there's no reason for the orbits to be in any given month, there's not that many good ones, so they're not evenly distributed throughout the year. Some periods must be better than others.

The Taurids are associated with an ancient comet, and are encountered yearly in October and November, but may have dramatically different rates from year to year.

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