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Schoolboy Corrects NASA's Math On Killer Asteroid
spiracle writes "A German schoolboy, Nico Marquardt, has revised NASA's figures for the chances that the Apophis asteroid will hit earth. Apparently if the asteroid hits a satellite in 2029, its path could be diverted enough to cause it to collide with Earth on the next orbit, in 2036. NASA had calculated the chances as 1 in 45,000 but the 13-year-old, in his science project, made it 1 in 450. NASA agreed." Update: 04/16 16:47 GMT by Z : This is not entirely accurate, it turns out — more details.
I guess we might as well start an impendingdoom tag meme?
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...is if this asteroid can't even properly hit Earth, as big a target as it is, how the hell is it going to hit a satellite -- even if there are 40,000 of them?
If the entire increase in risk is due to this, that means he's basically giving this thing a 1 in 450 chance to hit a satellite. Somehow, I don't think so.
Or faced political pressure to predict something other than a fairly decent chance of doom. I mean really: does anyone think a 13-year-old outsmarted every scientist at NASA?
You and your parent need to RTFA. The kid didn't find a math error. He found a conceptual error.
And this observation is applicable for exactly what reason? Are you claiming that NASA management is screwing up the calculations? Or are you just talking out of your ass and trying to insinuate that NASA is always incompetent in whatever it does?
Btw, in case you are not aware, the NEO office is at JPL--not JSC. And JPL is run by Caltech for NASA--not directly by NASA.
Now that we have that cleared up you should feel free to continue your bullshitting and insinuating via hearsay.
This does not sound right. The article states that Apophis has a mass of 200 billion tonnes. How would colliding with a satellite which except for the ISS max out at about 20 tonnes do anything at all to Apophis' orbit? Forget the link to the wire story where is a link to NASA statement that the impact chance is really 1 in 450?
Thinking about the likelihood of a satellite collision in the first place, and then the probability that it would adjust the orbit of Apophis so that it would impact Earth, I'm going to have to intuitively agree with NASA on this one. The odds of an impact with a satellite should be vastly below 1 in 450, which alone means that this should be wrong. Let's wait for a real account of this, not a pop-media summary with a lot of holes.
"I zero-index my hamsters" - Willtor (147206)
Let's see. We begin with the original source of data, "telescopic observations." Good, but perhaps a bit, shall we say, lacking in nine-digit precision. Then we add the element of a bright schoolboy (always a favorite in the papers) doing something big and being validated (instantly!) by "NASA" (not a person, but apparently the entire agency). Oh, and "NASA" told "ESA", but we still don't have the identity of anyone other than the putative schoolboy.
So far, doing well.
Then we hit the big problems. First, we have the scare factor of "40,000" satellites surrounding Earth. Most of which, actually, are in LEO, with a few more in geosynchronous orbit. Which makes the space around the Earth only about 99.999% empty space, rather than a few more nines. As it turns out, space is big.
But it sounds good to imply that somehow there's this asteroid belt around the earth, and that the "killer" asteroid might hit a satellite.
Well, WHICH ONE? They have a lot of different masses, they are going in different directions, and we pretty much have to get a specific momentum change in the right direction in order to get just the right perturbation. Hitting a small piece of space junk is one thing, but the variation in weight of those "40,000" satellites is orders of magnitude. And that makes a big difference in orbital perturbation, even if the difference in orbital velocity is small compared to the velocity of the asteroid. We're talking about a subtle effect here.
And let's not figure in things like elastic collisions, off-center collisions, pieces flying off, or anything else. Nope, it's gonna happen perfectly, just like that seven-ball four-cushion bank shot we all can hit again and again.
Heck, they even called the pocket. Right into the Atlantic, after an orbit measuring in the decades. Now I will grant that the orbit is pretty well known, but again, that little "satellite assist" must be just precise as heck.
A nice touch gives us the "destroy both coasts and darken the world indefinitely." While it's good to be so certain, couldn't they be more specific about the method of destruction? Seeing as how they apparently know everything else, and all.
And finally, we have the 450:1 odds. Not 500:1, and certainly not 1000:1, but exactly 450. Cool. About as believable as my old homework excuses, but infinitely cooler. Can you say "significant figures"? I knew you could.
I think it's what you get when you let AFP (my source of news of the world for sure) loose in spring.
Once you're below a certain threshold, a few more zeros really does not change anything. Very unlikely vs extremely unlikely is hardly relevant. Increasing my chances of being hit by an asteroid by 500 times still does not put it on the radar. Increasing my chance of a car crash by 50% is much more important.
Engineering is the art of compromise.
Right, but the asteroid has hit a satellite between now and then, a satellite which has, apparently, increased its chance of hitting earth from 1 in 45000 to 1 in 450, which means that its trajectory has changed fairly significantly. In particular, its orbital period has probably changed, which makes it seem unlikely that we can say anything accurate about an impact time 7 years later. There's only a four hour window to hit the Atlantic.
Not only that, but the Atlantic only covers one fifth of the earth's surface, which means that even if, despite all the uncertainty, we knew exactly what time it would hit the earth, the Atlantic would cover at most about one half of the target. So I very much doubt that anyone who knows what they are doing would be prepared to "agree" that it will hit the Atlantic.
So I smell bullshit in the science lab. To be fair, it's possible that a bad translation from the original German article was required as a catalyst.
seriously ... BS detector is flashing red on this whole article.
But it does raise the point that apocalypse cults are best kept away from space tech.
Is that in the same way that ~250k people in India, Indonesia, Malaysia, the Maldives, Myanmar, Somalia, Sri Lanka and Thailand "got wet" after the earthquake in 2004?
[b.belong('us') for b in bases if b.owner() == 'you']
NASA is a big organization. Perhaps he's trying to insinuate that NASA is sometimes incompetent at some things it does (imperial vs. metric anyone?) I'm about as unamerican as any other non-USian citizen out there, but I've dealt with big organizations, government or otherwise before,and I've seen my share of corporate stupidity and employee stupidity, which may be not even this case, because, as big as NASA is, they don't cater for the underachieving.
Stupidity is an equal opportunity striker.
Fellow slashdotter Bill Dog
You, wouldn't have to deflect it much. just a fraction of a fraction of a degree. We're talking about huge distances here. Ever played pool on a pool table with sand? Try making that rebound shot, where you bounce it off three bumpers from one corner and sink it in the fourth corner with a single piece of sand in the the path of travel. Now multiple by a factor of a billion and you begin to get the idea. When Russia launched a probe to the Moon, they were off by less than a degree and missed the Moon by something on the order of a million miles. Don' forget Apophis is going pretty damn fast too. Action - reaction and all that. Whether the satellite is traveling towards or away, etc.
I'd love to see the computer-cluster this kid calculated the 100k+ iterations of the many-bodied system of time-retarded lagrangians required to solve something like this. His parents power bill has to be insane. Considering uncertainties involved in orbital trajectories and timing for asteroids like this, 100k might even be a low number of runs for something like this. The number of satellites in orbit, their varying masses, uncertainty in the current un-colided trajectory, etc. can't possibly create a situation where you have improved odds of impact anyways. There is actually a greater solid angle of impact for collisions that would decrease the likelihood of eventual earth impact than increase it. Maybe these odds are after the most favorable possible satellite impact plus the help of magical space faries?
If merely randomly hitting a satellite will make it impact earth, than a targeted hit by another satellite will make it not impact earth.
So if this report is true (which I very much doubt), it in itself provides the answer.
You were probably going for +5, Funny, but I think you might be on to something. Turn this sucker over to some company, who can have all the ore, as long as they make sure to grab it all and address the safety concerns before it gets here.
Stasis is death. Embrace change.
Yeah, it's clearly typical science journalism. For now, though I'm willing to believe there might be something there. I'd like to see an official NASA report on the story.
Of course, no one's mentioned that we'll know much more precisely what will happen by 2029 -- not only whether there's a concern at all, but which satellite would be hit. In which case we could, you know, move the satellite. The do have some station-keeping capability, after all. And even the dead ones could be moved by a tug, given a small amount of notice and a really good reason (I think this qualifies).
So I'll bite the bullet.
First off... how does a 200,000,000,000 tonne asteroid (200,000,000,000,000 kg) travelling at any substantial inter-planetary speed be deflected by a satellite travelling at 3070 m/s and at most wieghing 10,000kg?
Of course thats presuming an elelastic collision as opposed to the satellite deflecting off the asteroid in a cloud of debris.
Its been a while since I've done any physics, and I'm just grabbing numbers from the article (which are likely to be wrong anyways).
But to bring it all together in a car analogy for the fellow /.ers... How does a .22 bullet deflect an oncoming semitruck forcing into the little old lady on the sidewalk?
True, perhaps, but 1 Mt St Helens isn't that terrible contained in a relatively small area (of course, with anything of this magnitude small is a very relative term). If something like this were to hit in the pacific, what would the tsunami produced by such an event be like?
The wikipedia article for the 2004 Indian Ocean tsunami states that the earthquake released around the equivalent of 1502 Hiroshimas, so we're talking over an order of magnitude difference. That said, a lot of the death toll in 2004 was caused by lack of warning, which certainly won't be an issue in the event of an impact, so I suppose that it will balance out somewhat.
As other readers have pointed out, the Asteroid actually weighs 21 Megatonnes, not 200 Gigatonnes.
Journalists are the only people worse on Maths than both NASA and German school boys.
Err...yes, I would agree with that sentiment, but I think that's exactly why they wouldn't predict doom.
Bear with me for a moment (and feel free to rip the argument apart later): if NASA predicted impeding doom from the asteroid then people would panic and NASA would receive tons of funding, but for all the wrong reasons. Instead of attempting to focus on research and possible Mars visits they would be forced to spend tons of time and effort trying to avert an Armageddon that would likely never come. This would most likely set the program years back.
If they instead ignored the thing until it was certain to collide with the Earth, then they would have several years to find a relatively easy solution, and up until that point they would have twenty years of advances under their belt.
Maybe this is the lack of sleep combined with hours of work and six cups of coffee talking, but I think that NASA had/has very good reasons for keeping this thing quiet.
As did everyone else who replied to you. If it walks like a duck and quacks like a duck..
Stupid people think it's cool. Smart people thinks it's a joke; also cool.
Why don't we just take all satellites out of orbit starting now, or right before the potential event in 2027? Seems a little cheaper than building a huge orbiter and weapon to move the asteroid.
And where on THEIR website is this mentioned...?
Oh come on, get with the program. Mt. St. Helens was in America so it was obviously the most important. What are you, a freaking communist?
Chernobyl 'not a wildlife haven' - BBC News
Given the track record on space propulsion advances over the last twenty years, I'm not going to put much faith in a game-changing engine appearing in the next twenty.
If they instead ignored the thing until it was certain to collide with the Earth, then they would have several years to find a relatively easy solution, and up until that point they would have twenty years of advances under their belt.The "relatively easy solution" is to go push it as soon as possible. The sooner you push, the less pushing you have to do. With Apophis in particular, you want to get your pushing done before the 2029 flyby, as it will magnify the effect.
(of course, it turns out the kid was wrong, but the point stands)
But then again, I could be wrong.
http://www.theregister.co.uk/2008/04/16/esa_german_schoolboy_apophis_denial/
You ever go to the mall and drop a quarter in one of those funnel things? You know how it rolls around and around? Now, imagine putting something in front of the quarter...What will happen?
It'll slow down slightly, and the loss in speed will cause it to zip down the funnel.
That's what we're dealing with here. If this thing loses enough velocity, our gravity well will suck it in. If we could give it a push as it is on it's way past us, sure, we could get rid of it, but putting things in front of it is always going to be bad for us.
ad logicam Claiming a proposition is false because it was presented as the conclusion of a fallacious argument.
So in Slashdot's world "not entirely accurate" is the same thing as "completely, utterly, bloody false." Good to know.