On 02/17/2013 04:36 PM, bob haller wrote: > On Feb 17, 12:28 pm, "DonH"<donlhumphr...@bigpond.com> wrote: >> "Robert Clark"<rgregorycl...@yahoo.com> wrote in message >> >> news:firstname.lastname@example.org... >> >>> I really don't like coincidences in science. Reports are asteroids >>> the size of 2012 DA14 getting this close occur about once in 30 >>> years. And meteors the size of the Russian one enter our atmosphere >>> about similar frequency. But the problem is their both occurring in >>> the same 24 hour period. If you imagine the asteroid arriving on a >>> particular day, the question to ask is what is the probability of the >>> Russian meteor arriving on that same day? Once in 30 years, and then >>> 365 days in a year, means the chance of this happening is like 1 in >>> 10,000. That's disturbingly unlikely. >>> On the other hand if this really is just coincidence, then it should >>> be kept in mind that chances this low have been quoted in regards to >>> large asteroids impacting Earth in our lifetime. >> >>> Bob Clark >> >> # So, is there any evidence that the meteor "pealed off" from the asteroid, >> or that there is some connection between the two - apart from coincidence of >> occurrence? > > Think of playing pool, in a larger sense thats where we live. > > The two may not be releated, but could be, as part of some collisions > perhaps before any of us were born..... > > Its possible our earth may be in a area of space with more litter than > usual. > > People will get more interested if we get more incoming. Or nasa > tracks the one that missed and finds its perturbed by earths gravity > and will be back to impact somewhere on our planet
Meteor showers like the Perseids have a so-called radiant point in Perseus, from which they trace back. This is because the fragments are travelling in parallel directions w.r.t. the "fixed" solar system and the earth passes through this bunch of objects whose orbits "intersect" earth's orbit at one point in the yearly cycle.