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

Hang on ...

[attonitus]

... it will create a ball of iron and iridium 320 metres (1049 feet) wide and weighing 200 billion tonnes ... If this thing weighs 200 billion tonnes, it seems surprising that hitting a satellite is going to divert its course very significantly (unless that satellite is the moon). And:

NASA and Marquardt agree that ... [it] will crash into the Atlantic ocean Ah, so there's only a 1 in 450 chance of it hitting earth, but we know which ocean it will land in if it does (7 years after it hits the satellite).

Next week: 13 year old boy discovers new chemical reaction in which a combination of scientifically illiterate PR bunnies and sub-editors produces large quantities of bullshit.

Re:Friday the 13th

[terrymr]

> 26,000 Hirshimas

So a little less than 1 Mt St Helens then.

Re:So if it does hit a sat will we know about it?

[Anonymous Coward]

And how long will it take to figure out if we're boned? 2 years? That leaves about 5 years to do something about it.. or, ya know, go on a long killing spree.

That's the depressing part.

To answer your question: Probably a few months after the 2027 encounter (and hypothetical collision with the satellite), but at that point, it'll be impossible to do anything about it in the 9 years between 2027 and 2036.

The right strategy is to use the 20 years between now and 2027 to build an orbiter/lander (with a big-ass nuke, nuclear reactor powering a big-ass laser, or big-ass solar sail of reflective/absorptive paint -- and as much as I like nukes, the big can of paint's probably the best way to go -- attached).

We use the 20 years to build the orbiter/lander. We send it up to rendezvous or orbit in 2027. If Apophis smacks into a satellite (or we're just unlucky), we'll have an orbiter and countermeasures in orbit around the asteroid on that pass, and those countermeasures will have nine years in which to do their work. A nuke's pretty cool, but it can't compete with nine years of momentum transfer from the sun shining on a rock painted white on one side and black on the other side.

Suppose we cut it short and by 2027 we still don't have any good countermeasures - just a crappy-ass nuke as a last-ditch measure. Even if we go this route, we've still got 9 years for this orbiter to give us an exact gravity map of this object, and we'll have a couple of years after that to figure out where to land the nuke for maximum trajectory deflection away from the earth. (Hell, if we get the orbiter up there early enough in 2027, we can blow the nuke at/near closest approach to Earth and guarantee a miss in 2036!)

But we're short-sighted. So we'll do nothing between now and 2027. And odds are it'll sail on by in 2027 and we'll conclude that the odds of an impact in 2036 are only one in a few tens of thousands. But what an irony -- if we're wrong, then it'll be too late in 2028 for us to send anything to catch up to the rock and do anything about it. For the sake of a month's pork-barrel spending in Iraq, we'll condemn a few billion of our fellow humans to certain death in 2036.

If it's not Apophis, it'll be some other rock in the next few centuries. Just like the dinosaurs, we'll go extinct because we don't have a space programme. Unlike the dinosaurs, this time around, we'll deserve it.

Re:Where's the math?

[turkeyfish]

Even so, it would be nice to see the math. The only place I have seen such equations solved is in Feynman's Physics volumes, which unfortunately I lost to Katrina.

What is the error estimate on the precise trajectory of the asteroid and its velocity? How can they arrive at a 400 m window, when they don't even have a good tracking of all the space junk in orbit? How many satelites were taken into consideration in reaching the 1:450 number? Can these really be ignored if the trajectory is to be computed this precisely? Have all the calculations taken into account numerical precision associated with floating point representation? Have the gravitational effects of the other planets been adequately accounted for? With what precision?

Just questions it would be interesting to look at to assess how these figures are arrived at.
It wouold be instructive to see what figures NASA or the German schoolboy used in their equations.

Re:Friday the 13th

[Kjella]

The energy content is said to be 26,000 Hiroshimas Huh, wait a second. The estimates for the Hiroshima bomb is 13-16 kiloton which would make it in the 340-415 megaton range. That's just 8 times the Tsar Bomba of 50 megaton the Soviets tested, and last I checked the world did fine. That number must be way off or the potential damages way exaggerated.