Monday, May 26, 2008
Apophis risk not increased: science fair judges, world media screw up big time
First the story appeared on April 4 in Germany's 'leading' tabloid ("I have calculated the end of the world ... and NASA says, I'm right"), later in more serious papers ("Nico and the end of the world") - and today, thanks apparently to an AFP story where the writer hadn't found it necessary to check anything, it has taken off around the world. Alas: it's absolute nonsense! The claim is that a 13-year old German schoolboy "discovered" - while working on an entry for a major German science competition - that the 2036 impact probability of asteroid Apophis is not 1:45,000 as the NASA calculation says but actually 100 times higher. Because during the 2029 approach the asteroid would hit a geostationary satellite and be deflected into a much more dangerous orbit. The newspapers also claimed that this boy not only was awarded several prizes for his paper but that NASA had "conceded" that he got it right and they were wrong. We're all doomed, right?Well, here's what NASA's NEO guru Don Yeomans told this blog yesterday: "We have not corresponded with this young man and this story is absurd, a hoax or both. During its 2029 Earth close approach, Apophis will approach the Earth to about 38,900 km, well inside the geosynchronous distance at 42,240 km. However, the asteroid will cross the equatorial belt at a distance of 51,000 km - well outside the geosynchronous distance. Since the uncertainty on Apophis' position during the Earth close approach is about 1500 km, Apophis cannot approach an Earth satellite. Apophis will not cross the moon's orbital plane at the Moon's orbital distance so it cannot approach the moon either." And here's how one of the German scientists mentioned in the first story, celestial dynamics expert Frank Spahn from Potsdam University, explained events to this blog today: "I indeed had contact with this engaged boy - he asked me which perturbations/forces determine Apophis' orbit and especially during the close flybys. You know that I deal with kinetic theory & celestial mech. in the context of planetary rings, preplanetary disks etc. I explained him the 3 and 4 body problem and gravitational interactions in general. He did not tell me about his idea to consider a collision. This was in January or February. The next time when I heard of him was in in the boulevard journaillie "Bild" - together with my name.I asked him to meet me (last Friday), he told me about the asteroid - satellite collision thing (after I asked him how he calculated and "corrected" the NASA result). Then I showed him at the black board about the extremely small collision probability (frequency) with such an object. Seeing the arising problems I attended the set of [German TV news station] N24 and explained the leading responsible person that I appreciate the engagement of that young student but simultaneously I express that one has to mention the low probability of such a collision plus expressing that this is not a correction to NASA. The filming session went on and I had to leave for another meeting. The I saw yesterday that nonsens in TV - and I am shocked. By the way - I haven't seen that paper and the work sofar, Nico told me that his computer disk had a virus so that only hard copies are available which are with the referees of the contest at the moment. So - I do not know how he could have won the competition, obviously the referees were no experts."Nor were the writers for the German newspapers or AFP - none of which bothered to ask NASA directly or just consult the impact risk page for Apophis. This is clearly the most used and abused Near Earth Asteroid in many years: Still called 2004 MN4 it briefly reached a record high impact probability for 2029 in late 2004 which quickly evaporated (as always in these cases - so far) when radar data nailed down its orbit in early 2005. And in the following months the remaining impact probability for 2036 also continued to dwindle, to the present 1 in 45,000: You can follow the real science - and the triumph of radar astrometry - on this dedicated NASA website. Which certain Jugend Forscht judges and journalists should have consulted, too ...
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