On 02/19/2013 02:52 PM, Robert Clark wrote: > On Feb 18, 8:46 am, Bjørn Sørheim<bsoer...@nixspam.online.no> wrote: >> Here you made a MAJOR error. Your argument is way stronger, my friend. >> You probably didn't do much probability computations? >> >> I just choose to accept your numbers for probability of the two >> phenomena, as they seem to on the right level. >> So the probability of these two different phenomena occuring within >> 24hours is found by multiplying their probability for each separate >> incident. If the probability for the asteroid occuring is Pa, and the >> meteor occuring is Pm, then the two on the same day is Pa times Pm. So >> calculating the probability is like this: >> 1/30x365x30x365=1/119902500, that is 1 over 100 million! >> So you have to start the discussion over again >> with this imensly low probability in mind. >> >> CNN posted on Saturday an article where an astronomer from Yale came >> to a very similar number. Unfortunately she shot her in the foot by >> saying the two trajectories/orbits were incompatiable. She probably >> bought that statement from NASA. >> Personally I think these two are connected, and the probability of >> them occuring together is as shown imensly low if not the first is >> producing the latter. So it questions why NASA, at least preliminary, >> said they were not connected. >> >> Bjørn Sørheim >> >> On Sun, 17 Feb 2013 07:26:38 -0800 (PST), 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. >> > > Here's the article by the Yale astronomer: > > A meteor and asteroid: 1 in 100 million odds. > By Meg Urry, Special to CNN > updated 8:16 PM EST, Mon February 18, 2013 > http://www.cnn.com/2013/02/16/opinion/urry-meteor-asteroid/index.html > > She states the two have very different orbits so they should be > unrelated, but acknowledges that the very low probability of their > both occurring so close to each other in time is puzzling. > In view of the very real dangers that would arise IF it is the case > they are related I think we should investigate some possible ways this > could occur. What I mean by this is cases where we assume asteroids > that make close approaches but do not impact, and therefore offer no > threat, still could have associated fragments that do impact. > One way is mentioned in the comment section to this NASA blog which > shows the different orbits of the asteroid and the meteor: > > How Do We Know the Russian Meteor and 2012 DA14 Aren't Related? > Posted on Feb 16, 2013 11:37:14 AM | William Cooke | 25 Comments | > http://blogs.nasa.gov/cm/blog/Watch%20the%20Skies/posts/post_1361037562855.html > > First though, note there are many ways a fragment could be separated > from the main asteroid. For instance some asteroids are "rubble > piles", loosely held together by gravity. In this case collisions > among the individual fragments could send a fragment away from the > main asteroid body. > Another is the obvious way of a collision with another asteroid or > meteor. > Still another would be outgassing of volatiles that provides another > force to separate a fragment from the asteroid. > > Then once the fragment is separated from the asteroid, over time, > since it was given some initial boost away and the asteroid gravity is > so small, it will travel further and further away from the asteroid, > though still in the same or close orbit. But the key point is > depending on the direction the fragment is sent, once the asteroid > comes around to the Earth or Moon or other planet on a close approach, > that fragment could be much closer to that large gravitating body than > the asteroid and therefore be sent on a different orbit. > Then on subsequent orbits it could impact the gravitating body. > Indeed it could even be captured by the gravitating body, such as the > Earth, depending on the speed it is traveling with respect to the > body. For instance asteroid 2012 DA14 was traveling at 18,641 mph, > about 8.3 km/s on closest approach. At the distance it passed the > Earth at 17,000 miles this is greater than escape velocity. But it's > less than escape velocity at the Earth's surface. So a fragment that > happened to be closer in to use on that closest approach could have > been captured. > > > Bob Clark >
This is what I think: it's too early to conclude or speculate that meteorites and asteroids now have an increased chance of impacting earth, on average.
-- dracut:/# lvm vgcfgrestore File descriptor 9 (/.console_lock) leaked on lvm invocation. Parent PID 993: sh Please specify a *single* volume group to restore.