Meteor science and binary thinking

So large one asteroid passed by and another hit the earth within 5 hours of each other, very long odds. 

http://www.cnn.com/2013/02/16/opinion/urry-meteor-asteroid/index.html?hpt=wo_c2

So on the one hand the trajectories of the two asteroids were very different, on the other, the odds of two such events occurring at about the same time look to be around 100 million to 1- from the limited information we have on such things.  

On the other hand, the trajectory of the asteroids is only one issue.

Both have orbits that go way off the elliptic plane, although they come close to the sun.  That suggests that neither orbit is mature.  Orbits should have a tendency to flatten to the elliptic plane of the solar system over time. 

Also, bodies that spend time above the elliptic usually spend time below the elliptic.  It is really incidental that the two asteroids were crossing the elliptic in close to opposite directions. 

So it is probable that both have been disturbed fairly recently, in cosmic terms. 

Note that within a day there was another fireball over California.

Here is one issue that is missing from the probability calculations: how many fragments were there? 

Lets say that there are two asteroids of comparable size in the asteroid belt in more or less stable orbits, but one is slightly higher than the other with respect to the elliptic.

What will happen if they collide? The higher one will be bounced up, the lower one bounced down, into new orbits.  

Let’s say one asteroid remains more or less intact from the collision but the other one fragments into many pieces. 

Because the new trajectories stem from the same incident, it is possible that they will be in sync, the one mostly whole asteroid and the fragments of the other one.  There may be some mathematical resonance there, and that the force up from the collision is going to equal the force down may cause them to cross the elliptic at similar times.  That’s a hypothesis.

Now if asteroid B had fragmented into a hundred two meter chunks and fanned out, then how do our odds look for hitting one of those fragments when they cross earth’s orbit and the elliptic?  Then the odds start to look a lot better.   Then the calculation of odds is off because we’re looking at it the wrong way, what are the odds on any day that we would randomly be hit by a meteor vs. what are the odds of hitting a meteor if the earth passes through a debris field.  

If there is a debris field moving in some kind of resonance with an asteroid because the trajectories of both are tied to the same event, the odds of both passing on the same day go way up. 

When considering whether two cosmic events are connected, you don’t  just go back and review the past 24 hours.