On Feb 17, 7:26 am, Robert Clark <rgregorycl...@yahoo.com> wrote: > 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
Incoming asteroids: ?This isn't over?, and nowadays it?s becoming a matter of how often those 1+ tonne rocks arrive. Fortunately most haven?t been of any sufficient metallicity density, as otherwise we?d be having to deal with those pesky craters from their impacts in addition to their supersonic entry of explosive shockwaves.
The arriving Sirius Oort cloud should offer at least a million times as many items as our Oort cloud has to offer, and perhaps on average offering a thousand times greater individual mass than items of our own Oort cloud has to offer. Most of us have no idea as to how massive those Sirius stars were to begin with, and we apparently don?t want to even contemplate as to the vast extent and massive nature of what its 8 light year radius Oort cloud has to offer as it encounters our Oort cloud.
This latest episode of asteroid encounters is becoming more than once a day that a 10+ tonne rock is directed at us or otherwise encountered by Earth. Is this going to be considered as too often or about right?
Obviously our planet encounters thousands of those kg or less massive items most every day (for the most part vaporizing well before surface contact), although lucky us because, apparently not much of anything encountered Earth or that of our naked moon throughout all of the Apollo era (even the sun remained passive, w/o UV or X-rays according to all of their Kodak film, not to mention local gamma and hard-X-rays were never an issue, as well as any contrast or dynamic range limitations of their Kodak film).
http://en.wikipedia.org/wiki/Meteorite According to many others that extensively research into this influx, whereas roughly 3650 thousand tonnes of stuff gets encountered by our planet every year (10,000 tonnes/day), and fortunately the vast majority (99.9%) being of items less than a kg that for the most part never reach the surface, although some meteorite remainders plus loads of the really small and low density stuff does manage to filter through. That?s getting those bigger than kg items down to the dull roar of perhaps 3650 tonnes per year or 10 tonnes/day that we?ll get to duck and take cover from, with perhaps only a small percentage (less than 25%) of that mass surviving its atmospheric entry enough to impact or land on the surface. Of course those of bigger than 10 tonne items stand a somewhat better chance of getting through and landing on the surface, especially if comprised of fused basalt or carbonado along with a sufficient percentage of heavy metals that make them diamagnetic or even paramagnetic.
There?s actually several teratonnes of paramagnetic basalt from encountering our physically dark moon, that?s on the surface and mostly hidden under water. Now that?s what a real nasty asteroid can deliver in addition to its ice and considerable lithobraking trauma.