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.

Comments

Other news stories on this

[goombah99]

NASA previously estimated the chance "Apophis" the asteroid would strike earth in 2027 was 1 in 45,000. But a german schoolboy, Nico Marquardt, pointed out that NASA overlooked the probability the asteroid would strike one of the 40,000 sattelites orbiting Earth and enter a new solar orbit intersecting Earth in 2036. A german newspaper reports that NASA now concurs the chance this will happen is about 1 in 450. If the 200 billion tonne ball of iridium and iron stikes the planet then it's literally light's out for earth: 800 foot tidal waves followed by an indefinite period of dust cloud covered darkness, not to mention metal vapor in the atmosphere. The original Slashdot discussion was in 2007 when the odds were better. At that time it was known that there was a small risk of a gravitational slingshot dropping it into the 2036 collisional orbit, however, to do so the asteroid had to pass through an improbable 400 meter wide strike zone to be properly deflected, as described in 2006 in Popular Science from 2006. Today's announcement of the new finding is here and here.

Re:Other news stories on this

[icebrain]

Multi-body orbit problems are highly chaotic... part of my senior design program was writing a program to simulate this asteroid's trajectory and a spacecraft observing it to refine the data, then projecting the refined data forward. Essentially, we wanted to find out how long we would need to observe said asteroid in order to get our error ellipse down to a specified level.

Turns out that even tiny velocity changes (well below 1m/s) had huge effects on the rest of the trajectory. If our spacecraft's first measurement was off in the wrong direction, our solution never converged in the time we needed it to.

Re:Other news stories on this

[Captain Nitpick]

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?

The same way sunlight can push a 270m rock around. Lest you think I am kidding, let's read what NASA has to say about that:

For example, the team found solar energy can cause between 20 and 740 km (12 and 460 miles) of position change over the next 22 years leading into the 2029 Earth encounter. But, only 7 years later, the effect on Apophis' predicted position can grow to between 520,000 and 30 million km (323,000 and 18.6 million miles; 0.0035-0.2 AU).

The effect of a small force integrated over years and a few billion miles produces a significant effect. In this case a relatively small deflection gets magnified by the 2029 flyby.

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).

It's obviously been a long time. Any impact will impart momentum to the asteroid. I don't know if you mean "elastic" or "inelastic", but it doesn't matter. Bits of satellite bouncing off the asteroid represent momentum transferred from the asteroid.

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?

Bad analogy. The elasticity and friction of the tires cancel out any effect of the impact. These effects don't exist for an asteroid.

A better analogy would be a bowling ball on a lane with one pin. There's a tiny pebble halfway down the lane. How does a 1g pebble deflect a 12 pound bowling ball? By getting run over. If the lane was 100 miles long, a grain of salt would have a significant effect on where the ball ends up.

Friday the 13th

[goombah99]

By the way, it passes by the earth in 2027 on friday the 13th. If it hit's it will hit in the pacific ocean. So California may get wet. The energy content is said to be 26,000 Hiroshimas which is not that much but recent calculation suggest is more than enough to darken the earth.

Re:Friday the 13th

[Bender0x7D1]

This asteroid would do 1d4 wombats of damage to each of the 130 million items in the Library of Congress. However, because of their binding (creating a rigid spine area), each of the 29 million books would take an additional 1d4 wombats of damage. So we can call the total damage as 159x10^6d4 wombats of damage to the Library of Congress.

Re:Where's the math?

[Anonymous Coward]

He didn't really correct NASA. He only extended their prediction: NASA predicted, correctly, that the asteroid had a 1 in 45,000 chance of hitting the earth in 2029. Nico pointed out, also correctly, apparently, that if the asteroid missed the earth but hit a satellite in 2029, then it would have a 1 in 450 chance of hitting the earth in 2036.

Original article

[ulash]

Here is the original article, in German, from the German newspaper. It looks like a professor helped him (Professor Spahn from Potsdam University). Bild is semi-infamous in Europe for sensationalizing stories but at least we know that the boy is real if nothing else...

Re:Not peer reviewed.

[commander_gallium]

You are right that NASA has not updated it's site since 2006. Just to be clear, the Impact Risk Page is kept current (pretty much to the day). You'll see the link for Apophis if you scroll down a little. If the odds of impact jumped by a factor of 100, this would be one of the first places to show it.

Re:Not Math Error

[JLF65]

They didn't forget about them. There is almost no chance a satellite will be struck. If you read the original FA, you'd see that a) the asteroid will pass inside the orbit of them, b) it will pass at a 40 degree angle to them, and c) when the satellite does reach the distance the satellites orbit at, it'll be well beyond the region the satellites are in.

The kid calculated the odds of the asteroid hitting the earth IF the asteroid hit a satellite JUST PERFECTLY. The odds of the asteroid hitting a satellite, much less just right for that to occur, are remote at best. This is just media hype to increase ratings.

Re:Google translation of German source

[thodi]

No need to translate it to make it hilarious:
a) The source "newspaper" is Germany's biggest tabloid - with as much knowledge on astrophysics as a kindergarten kid
b) No 13 year old German kid says "stuerben"

Correction: Source wrong

[Peregr1n]

Sorry to burst the balloon, but apart from the one German article that was picked up by AFP, there's no source for this story. And NASA and the ESA deny ever saying that the schoolboy was right. It seems that the schoolboy's sums were wrong, and NASA's original workings are right. More info: http://www.theregister.co.uk/2008/04/16/esa_german_schoolboy_apophis_denial/ I'd file this under 'web hoax' or 'lazy journalists pick up on anything sensational'

The News is wrong

[phoenix_nz]

Just in case anyone still believes we'll all be killed by an asteroid in 2029 or 2036, here's an article from El Reg, claiming that the boy got it all wrong.
I guess we'll have to live with the miniscule 1 in 45,000 chance.

link to article:
http://www.theregister.co.uk/2008/04/16/esa_german_schoolboy_apophis_denial/