This area will cover relevant news of the threat to the planet from Near Earth Objects (NEOs) including concepts and designs for mitigation. All opinions are those of the author.

16 April 2008

Correcting Media Sensationalism on Apophis, 13 year old kid, and NASA

Ok. Not True. Here is the history's judgment on this media blow up over a 13 year old's prediction that Apophis has a 1 in 450 chance of hitting the Earth in 2036 (not true, actually it is 1 in 45,000). Here is NASA's statement and Daniel Fischer's blog entry explaining the situation.


From Don Yeomans at NASA JPL NEO Site...

16 April 2008:

In response to inquiries, accidental impact with an artificial satellite in 2029 is vanishingly unlikely. As mentioned above, (1) Apophis does not pass near the zones where most satellites are located and (2) man-made satellites and Apophis both have small cross-sectional areas. Even if a high-velocity impact occurred, a large satellite could change Apophis' position 7 years later (in 2036) by only 100's of km at most. This is less than 1/10th the size of the smallest issues considered in the paper, very much in the noise of the calculations, and can have no meaningful effect on Earth impact probability estimation (which already incorporates more than 30 million km of uncertainty). At such a late date, impact with an artificial satellite would be like a bug on the windshield of Apophis. Deflection efforts are dependent on being early enough to leverage the dynamics of the 2029 encounter. Events during the encounter lack such leverage.

Link: JPL NEO Page on Apophis


NASA Statement on Student Asteroid Calculations
16 April 2008

WASHINGTON -- The Near-Earth Object Program Office at NASA's Jet Propulsion Laboratory in Pasadena, Calif., has not changed its current estimates for the very low probability (1 in 45,000) of an Earth impact by the asteroid Apophis in 2036.

Contrary to recent press reports, NASA offices involved in near-Earth object research were not contacted and have had no correspondence with a young German student, who claims the Apophis impact probability is far higher than the current estimate.

This student's conclusion reportedly is based on the possibility of a collision with an artificial satellite during the asteroid's close approach in April 2029. However, the asteroid will not pass near the main belt of geosynchronous satellites in 2029, and the chance of a collision with a satellite is exceedingly remote.

Therefore, consideration of this satellite collision scenario does not affect the current impact probability estimate for Apophis, which remains at 1 in 45,000.

Link: NASA Statement


"Apophis risk not increased: science fair judges, world media screw up big time"
16 April 2008

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 ...

Link: Daniel Fischer's Blog Entry

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