– some clarifications.
Today many of my foreign friends asked me about meteorite strike in Chelyabinsk today, so I decided to put some information here, looks like there is interest in it.
First of all, there is not so much in common between today's event and Tunguska event – yes, both of them took place in Russia, in both cases we had air explosions, but that's pretty much all. Happily Chelyabinsk's blast wasn't nearly as powerful as Tunguska's. Today we had something like 10-20 kiloton explosion (as least powerful atomic bomb), and it was high in the air, so shock wave wasn't as dreadful as it could be. And in Tunguska we had 30 – 50 megaton blast – as if most powerful hydrogen bomb was exploded there. And, of course, it should be much easier to understand nature of Chelyabinsk's explosion – we have plenty material to analyze. And we don't know for sure, what exploded in Tunguska more than a century ago – was it an asteroid, a small comet, or maybe something else?
Second, looks like Chelyabinsk's meteorite had nothing in common with 2012 DA14 asteroid flying near us right now. Trajectories was way too different to assume that meteorite was 2012 DA14's remnant. Just coincidence.
And last – many people wondered, why so much Russian drivers drive with video cams enabled. There were plenty of different assumptions – they say that it is required by law in Russia, they say that all cars here are pre-equipped with cameras, they say that installed camera will reduce your insurance expenses. Actually non of this statements are true – except, partially, the last one. Yes, this is special car cameras (so called 'video registrars'), but you should buy it and install it on your own. Plenty of people in Russia do this, because way too often only video can prove your innocence in case of car crash. Of course, that can reduce your insurance expenses, as it would be more cheap to insure your car in case you had no road accidents you were guilt of.