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Debunking the story about the Russian meteor event

This Friday, about 15 hours apart, two rare events occured:

  1. A 15 meters meteor exploded above Russia
  2. A 50 meters meteorite missed Earth by less than 20,000 miles

Astronomers claim that both events are unrelated, because the meteorites in question were flying in opposite directions (South to North vs. North to South).

Here I claim that the 2 events are related, and that indeed, we are dealing with two fragments of the same space rock (the Russian explosion is NOT a test nuke from some rogue entity).

1. The probabilities do not make sense

The first event is said to happen every 100 years. The second every 40 years. Thus, if unrelated, the chance that (1) and (2) occur on a same year is 0.025%. The chance that they occur on a same day is 0.000068%. The chance that in your lifetime, you see such a coincidence is about 75 times higher. Now the chance that any kind of extremely rare event occur during your lifetime is actually very high, but that's another story.

One might suspect that some of the above numbers are wrong: maybe 15, 50, 40 or 100 is wrong, thus making this coincidence far more likely than it seems at first glance. However, I believe that these numbers are accurate enough to make the probability incredibly small, and I persist with my belief that indeed, the two events are thus related. Read below for my explanation.

2. Look at the graph below

The fact that both rocks were flying in total opposite directions actually makes perfect sense! Below A and B represent respectively the smaller and larger space rocks. Metorites are known to break due to tidal (gravitional) forces when approaching large bodies (Sun or Jupiter - or it might have happened long ago).

The graph speaks for itself.

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Comment by David J Corliss on April 4, 2013 at 1:11pm

Robert writes: "Rather, I imagine that this asteroid has during its lifetime (which is measured in billions of years) had (and survived) some close encounters with other larger objects in the solar system (i.e., planets).   The tidal forces of one of the events could easily have broken the asteroid into a few pieces all of which survived and all of which then continue on similar but not identical orbits."

There are several problems with this - reasons that just don't fit the data NASA and others have collected. (1) This hypothesis requires the composition of the two asteroids to be very similar, since they are both parts of th same object. Instead, the compositions are known to be different. (2) The orbits of the two asteroids has been calculated with a great deal of precision. They do not intersect with any large astronomical bodies (anytihng sufficient to break up a piece of rock like this stony asteroid. Comets are generally fairly fragile but asteroids are not.) (3) Peer review. The article cited below plots the orbits; it also gives a large number of academic citations. I am not asking you to believe a PhD astrophyscist (me) on this: I am asking you to consider the broad range of academic, peer-reviewed analysis on the subject. No astrophycist of which I am aware is suggesting that these asteroids were two pieces of the same object, how ever long separated in time. You can talk about a NASA conspiracy if you like but I don't think NASA will have coerced the Russians, British, Finns, Australians and others to independently come to the same conclusions.

This is supposed to be a scientic discussion on a scientific venue but I have seen very little science going on here. Instead, conjecture hase been piled on top of conjecture with little or no attempt to seek out the actual data well-known to exist on this event. It's time for people to stop talking and do their home work. A lot of data is availiable on this event. We are supposed to be the people who come up with data-drive solutions, not "gee - let me make guess about something I know very little about and defend that unfounded guess against all comers using conjecture instead of data." #professionaldisappointment

http://en.wikipedia.org/wiki/2013_Russian_meteor_event#Coincidental...

Comment by Robert Vanderbei on April 4, 2013 at 12:28pm

You have not described the scenario I have in mind.   I do not imagine that there was some recent undetected catastrophic event that busted up the asteroid.  

Rather, I imagine that this asteroid has during its lifetime (which is measured in billions of years) had (and survived) some close encounters with other larger objects in the solar system (i.e., planets).   The tidal forces of one of the events could easily have broken the asteroid into a few pieces all of which survived and all of which then continue on similar but not identical orbits.  

Yes, the piece that hit over Russia could easily have been "ahead" in its orbit.   And, if the severance from the earlier close encounter happened 10's or 100's or ... years ago, then being ahead by 16 hours is nothing.   So, no, I am not suggesting a last-minute massive explosion.  Nothing of that sort.  

No one saw the direction from which the fragment approached the Earth.   Your assertion that it came from the opposite direction (where by opposite I think you mean orthogonal) assumes without questioning that the NASA analysis is correct.   I'm not saying it isn't.   I'm asking for the level of confidence, which wasn't reported.   Same for the composition.  

So, yes, at the moment I still think that the common origin hypothesis is more probable that NASA's theory.   But, I am willing to change my mind.

Comment by John Morrow on April 4, 2013 at 12:11pm

I don't mean to be argumentative, but you computed a probability based on pretty broad guesses about the size of the rocks and some estimate of the average probability of two such rocks showing up at the same time.  This is hardly hard science.

If you want to discuss probability, let's talk about the probability of this:

- a well known and carefully tracked near earth asteroid suffered a catastrophic yet strangely undetected traumatic event that broke off a large piece

- this event somehow didn't change the trajectory of the main asteroid

- the fragment that broke off somehow accelerated enough to arrive 16 hours ahead of the main asteroid, suggesting a massive explosion or some other infusion of energy that was, again, undetectable and that, again, apparently had no impact on the asteroid's trajectory

- the fragment somehow ends up approaching earth from the opposite direction of the main asteroid, despite traveling considerably faster than the escape velocity necessary to not be captured by earth's gravity (NASA suggests its velocity about 18m/s, more than fast enough to blow right by the planet and certainly way too fast to cause it to do a 180 and slam into earth)

- and somehow the part that broke off just happens to be of a different composition from the main asteroid.

And you think that is more probable that NASA's theory?

Comment by Robert Vanderbei on April 4, 2013 at 12:05pm

The composition analysis certainly argues against them being from the same origin.   But, again, the NASA report did not give any measure of confidence.   Sure, small rocks found on the ground can be analyzed with great precision and yes we can be fairly (but not perfectly) confident that they are remnants of the meteor that exploded over Russia.   But, the analysis of the asteroid that flew by is  much more tenuous.   Even at its closest approach, it was a faint object.   Any spectra obtained of this object certainly has some error associated with it.  So, the question is:  what is the probability of an error in their assessment.   It is not zero.   What is it?  I know lots of physicists and astronomers.  They are, on the whole, very smart people.   But, they also are very self confident and often jump to conclusions prematurely.  That's my impression anyway.

Comment by Robert D. Brown III on April 4, 2013 at 11:51am

The discussion so far in this thread seems focused on the base rate frequency of 'simultaneous' events of this magnitude AND their trajectory, and the analysis seems to imply that we should adopt a high degree of belief that the events are related. Yet the composition assertion by NASA would seem to negate or strongly attenuate the inference we derive from that joint proposition. Do I understand that correctly?

Comment by Robert Vanderbei on April 4, 2013 at 11:38am

Yes, that is the question.

Comment by Robert D. Brown III on April 4, 2013 at 10:14am

Help me understand this. NASA offers two lines of analysis: trajectory and composition of the objects. According to NASA, "A second reason we know the two asteroids approaching Earth on Feb. 15 were unrelated is their disparate compositions."

Isn't now the correct question to ask, "What is the probability that the two events are related given the base rate frequency of 'simultaneous' events of this magnitude AND their trajectory AND their composition?"

Comment by Robert Vanderbei on April 4, 2013 at 6:16am

I don't believe in believing.   I computed a probability using data.   It's a probability.   It's not a statement of fact.  My complaint is that the NASA scientists did not give any error bounds.   Why not and what are they?   They are not zero.

I understand gravity quite well (see, e.g., http://www.princeton.edu/%7Ervdb/WebGL/ducati.html and links thereon).  It's not about "gravity".   It's about the errors in analyzing the data which is mostly from dashcams of random people on the ground.

Comment by John Morrow on April 4, 2013 at 5:54am

Robert,

The problem is that your hypothesis is based entirely on speculation about probability while their claim is based in actual observed and analyzed scientific data. 

This is the kind of like drawing a conclusion about the cause of a car accident based on speculating about how unlikely it is that two purple Ferraris should collide at an intersection versus the other side examining all the data from the cars' black boxes and coming up with a different conclusion.

If you really believe that your hypothesis has merit, you should do the science.  Figure out what kind of gravitational forces would be required to cause the fragment to enter the atmosphere at the necessary angle to cause the impact event it did, assuming it recently broke off from the large asteroid.  Find some sort of scientific explanation for the apparently different compositions of the two rocks.  Come up with a scientifically valid explanation for the significant differences in speed.  Take the NASA data and find a scenario, consistent with the data and the laws of physics, that actually explains how these two events could be related.

You know... actual analysis.

Comment by Robert Vanderbei on April 4, 2013 at 4:50am

Hypothesis: The two asteroids are "related" (i.e., originated from a single asteroid breaking apart sometime in the not too distant past).

I accept this hypothesis. If I am wrong, I have made a "type II" error. Based on a statistical analysis of the frequency of these events, I have estimate the probability that I am making a type II error to be on the order of 1/50,000.

The folks at NASA reject the hypothesis. What is the probability that they are making a "type I" error? Well, they wrote with certainty. They would have us think that the probability of a type I error is zero. That's nonsense. Their data shows no error bars.

When integrating the equations of motion backwards in time, small errors quickly become large. It is entirely possible that the type I error is 1/100. If it is 1/100 then I'm sticking with my conclusion to accept the hypothesis. If it is 1/1,000,000, then I'd be inclined to reconsider. But, they have not given an honest assessment of this error probability. Hence, their analysis is interesting but it does not resolve the question.

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