German schoolboy, 13, corrects NASA's asteroid figures: paper

200 billion tonnes sounds too big. Is it correct?

Maby this wizz kid can tell us!

homeless people can correct nasa's estimates - unpopular opinion but correct

according to the current impact risk site
http://neo.jpl.na...942.html
it is 2.1e 10 kg which in tonnes is 2.1e 7, 2,100,000 only 2 million tonnes, with an impact energy od 4e 2 MT or 400 megatonne blast, they have not changed the page to reflec 1-450 yet if this story is right on thse odds this will be making the mainstream news pretty soon.

and you being proved wrong pretty soon, too bad that won't make the news. then perhaps, you'd think twice.

actually i hope you're right, 100%, I can't wait.

Okay first off NASA is capable of launching satellites into space - which requires a basic understanding of math.

Second - I think the kid probably didn't get the numbers right. I bet what NASA said was that he was correct in factoring in the possibility of the asteroid hitting a satellite; but not the actual number.

Seriously - so the kid calculated the trajectory of every one of those 40,000 satellites; as well as probable deflections based on the surface topography of the asteroid and the mass and shape of the satellites?

I say 1/450 is way too high if you're taking into consideration hitting a random object followed by an orbit around the sun. (it's a lot easier to not hit something than it is to hit in, in astronomical terms at least.)

>I say 1/450 is way too high...

Random speculation isn't very useful, either do your own calculations or leave it to others. Even 1/1 is not to high a probability if we know all the orbits with enough precision and they happen to intersect.

200 billion tonnes sounds too big. Is it correct?

Can some one check this approximate calculation i have done.
Assuming 50% Iron ore and 50% Iridium...

Volume of sphere = (4/3) * PI * radius^3

Radius taken as 160 m

Weight: Iron ore = 5000 Kg/m3, Iridium = 22000 kg/m3

Weight = (2/3) * PI * r3 * (5000 22000) kg
= (2/3) * 3.14 * 160^3 * (5000 22000) kg
= 2.093 * 4096000 * 27000 kg
= 2.314 * 10^11 kg
= 2.314 * 10^8 T
= 231.4 million T

(Above 2/3 taken as half is Iron and the other half is iridium and they are added in brackets)

As the percentages of iron and iridium can change the figure can be around 200 million Tons, not 200 billion according to my calculation...
Have I made any mistake ?

Note however that this figure may change a lot if the percentages are way different. (E.g. 95% iron and 5% iridium)

margin of error. we had this discussion on Fark.com sometime ago and came up with pretty much the same conclusion...wait and see what happens.

This article has garbled wording and is completely wrong anyway. Please get rid of it - it is unworthy of physorg.com. Other media are saying that the boy's calculations were wrong - and that neither NASA or ESA have said that anything was wrong with their calculations.

How large will Apophis appear in the sky from Earth surface, considering it'll pass INSIDE geostationary orbit?
250 meters 36.000.000 of meters apart should result in lass than 4/1000 degrees, right?

ryuuguu: 2.1e10 kg is 21 million tonnes

CSESL: Your calculation is right, but the NASA figures are density = 2600 kg/m3 and diameter = 250 m, giving 21 M tonnes as ryuuguu almost said. I guess the asteroid is not pure glittering metal, but more like a damp slag heap.

AFP need to buy some more monkeys, or more typewriters, or both.

Ummm, this article is wholly inaccurate. First of all, the newspaper is called "Potsdamer Neueste Nachrichten" NOT "Potsdamer Neuerster Nachrichten"

And second, it's not a "newspaper" as much as it is a TABLOID. And the register has looked into this and the verdict is that they made it up. PhysOrg, you disappoint me...

http://www.thereg..._denial/

um.....no one confirmed this kids observation that hitting a sattelite will change this things trajectory. just because the kid brought this up , doesnt' mean he's right.
z

Update: They have checked the kids number and apparently his math is wrong. No actual details yet.

not surprised.how is a small relatively slow moving sattelite going to affect the trajectory of a giant fast moving asteriod relative to the eart
what a bunch of hogshit
z

It is totally bogus to think anyone can predict the change in orbit caused by a collision between objects of such disparite shape and mass and project with any certainty 7 years after the collision. Besides having to predict which satellite would collide with the asteroid, if the collision is slightly off center, some of the energy will be converted into spin. The amount of energy converted into angular momentum requires knowledge of the mass distribution within the asteroid and the surface contours at the point of impact. It is certainly true that NASA may have neglected the potential of a sat impact, and that IF you redefine a "collision with earth" to include an impact on one of our sats, the odds of a colision would go up. But the sats are so small, the odds would still be terribly low. In any case, it is impossible for the kid to have projected the impact on odds some 7 years after the initial collision.

The kid (and the paper) had a lot of fun. Was it originally posted April 1 ???

Thanks for doing the math on the object mass.
Thanks also to the debunkers.
I would add that... as we haven't even solved the 3 body problem so we cannot predict with 'precission' the trajectory of any asteroid or planet for that matter. We resort to iterations and crude assumptions. The approximations become less significant as the object nears earth.

Not to worry, every Stargate watcher knows that SG-1 will save the Earth from Apophis.

Not to worry, every Stargate watcher knows that SG-1 will save the Earth from Apophis.

lol nice idea... May be they can do that opening a hyperspace window near earth thing they did for the Naquadah asteroid... :)

While the matter has now been resolved and the student's factors don't apply, it shows us how we still cast some doubt towards NASA, even thouugh they're right on this one..
John -- www.moonposter.ie

Gimme a break! I don't need to run any calculations to see that this story is a total screwup by the reporter. All you have to do is think skeptically to see that you can't significantly change the path of a train by placing a grain of sand on the tracks. And if you shot the grain of sand out of the new particle accelerator (if you could), it would only create a tiny mark on the train and still have insignificant affect on the direction of the train.

Pfff! This reporter should be put docked a week's pay and be sent to bed without supper. A reporter has a responsibility, and this person was totally irresponsible. And shame on the newspaper for printing it!

The following press release was posted yesterday at NASA's website (http://www.nasa.g...s.html), disputing essential elements of the above physorg.com article and re-affirming NASA's estimate of a 1 in 45,000 probability of impact of Apophis with Earth in 2036.

-----
April 16, 2008

Dwayne Brown
Headquarters, Washington
202-358-1726
dwayne.c.brown@nasa.gov

RELEASE: 08-103

NASA STATEMENT ON STUDENT ASTEROID CALCULATIONS

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.


-end-

The article is fishy because nobody is stepping up to confirm. It is also fishy in that enzo9026's link to the NASA statement is not working. Not sure why. I read it on ABC news' site.

My question is, where did the story come from in the first place, and how much checking was done in verification?

Journalism?

Here is the correct link to the NASA response:

http://www.nasa.g...ons.html

The article is fishy because of the prediction of the asteroid landing in the Atlantic Ocean, quite aside from anything else - think bout the accuracy of orbit determination that would be needed to make such a precise prediction.

Yeah, his calculations are right IF the asteroid hits a satellite. The chances of the asteroid hitting a satellite are next to NOTHING. So the boy is WRONG. Moral of the story: Don't believe what the German tabloids say!