How We Knew AL00667 Would Miss Earth

jefu writes "In January there seems to have been an incident in which it was thought that an object (asteroid) in space might have hit the earth within a couple of days of being spotted. It did miss, though. This story (from NASA/Ames) talks about the discovery of the object and the process that astronomers went through to determine if the asteroid was or was not a threat."

Comments

Wow

[rholliday]

I'm glad they're so confident. I, for one, find the thought terrifying. :)

Too bad they already made the (17 versions of) the movie about this. It's a nice story.

Re:Wow

[Anonymous Coward]

Wouldn't it be a bit difficult for me to die of cancer 240 million times? I can understand once but...

Interesting...

[Spazmasta]

that most people didn't hear about the asteroid until long after the near-miss was over. Seems to bring up the old argument of whether it'd be better to inform the public and try to do something about it or keep it under wraps and possibly die in blissful ignorance...

Re:Interesting...

[retards]

Well, yes, I guess you will die blissfully if you happen to be very near impact. Otherwise you can look forward to drowning in a tsunami, starving in the coming 5-year winter or just die at the looting of the local convenience store once the news breaks (duh, saltwater rain, 4 weeks of darkness, complete failure of all infrastructure, etc.).

It is a totally futile to even discuss what should be done if we are going to get hit, since there is nothing we can do about it at the moment. If the death of 80% of the worlds population and the fall of all governments is nigh, it hardly matters how people die or how the governmenst fall. It only confuses the real issue: how the hell are we going to fund a global defense system instead of funding luxury for 10% of the planet.

Recognition does not increase likelihood

[Effugas]

In the past fifty years, we have started to gain the technological capability to detect potential collisions with asteroids.

That does not make such a collision more likely in the next fifty years -- or hundred and fifty, or fifteen hundred. Significant and successful collision are _rare_, much rarer than earthquakes, tornados, or even human-caused meteorological effects (as in weather systems, not meteors).

It doesn't matter if we can see "just how close we came". It matters that we know, empirically, that there are vastly more pressing concerns.

What I don't want to see is an orbital weapons platform deployed under false premises. If the pretenses are true, that's a different story. Just don't tell me its to shoot down asteroids!

--Dan

Re:Recognition does not increase likelihood

[Eivind]

Sure. We know the chanses are low. Allthough we don't know exactly how low. We *do* know that in the last century alone we've had atleast a few impacts big enough that if they had happened to hit a major city rather than (for example) the tundra in Siberia, tens of thousands of dead would result.

We also know that major impacts, the sort that changes the climate over the entire globe and causes mass extinction of species has happened atleast on a few occasions.

But we don't really know enough to say anything about the true risks. For that reason alone, the first nice thing to do would probably be to increase funding for telescopes, radars and other instruments for better accessing the real risk. That is not a very expensive proposition, as this is an area that is very lowly funded today, a little bit of extra cash will go a long way towards establishing the real risks.

If we should do anything more depends on the risks and the costs of potential defences. It's a cost/benefit calculation.

You are rigth that ICBM-interception-systems are irrelevant for this purpose. All realistic systems for doing something about asteroid-impacts rely on the fact that a small change to the orbit of the thing a long distance from earth will result in a major change, enough to miss the earth, by the time it gets here. Changing the orbit in the last few hours is going to be impractical, it'd require huge amounts of energy. Sligthly more practical migth be blowing the thing up, which would result in a large number of smaller impacts instead of a single big one.

To stop a ICBM you need to hit it with, say, the explosive force of a hand-grenade. That's not going to cut it if you want to blow apart a asteroid of extinction-threathening size.

Re:Recognition does not increase likelihood

[Eivind]

Proven enough. Granted, there is some uncertanity around details like if the impact was the only reason for the mass extinction, or if other factors also played a role and so on. But there is no serious doubt in the scientific community that the earth was indeed hit by a pretty big asteroid. around the time the dinosaurs died out.

Besides, if you really doubt that this happens, you need only to take a look at the moon. It has no atmosphere which causes smaller asteroids to evaporate before impact, and also helps washing away the signs of impacts after they happen. It's probably a fair bet that the earth gets hit more often than the moon, given that it's so much larger. It's also a fair bet that anything that is big enough to create a major crater on the moon is also big enough to punch trough the atmosphere and create major destruction here.

Re:Flipped a coin?

[Drakin]

Um, the problem with that is the whole concept is to be dealing with targets launched from earth, at earth based targets.

Meaning they'd be pointing in the wrong direction.

Re:Flipped a coin?

[October_30th]

break it into something far less dangerous at worse.

So instead of one huge target you could in principle land on, you'd get a swarm of smaller but still deadly rocks that would rain devastation on Earth?

No, the only permanent solution to the extinction level event problem is to get some of us off this goddamn planet.

Re:Natural diaster...

[JavaLord]

Mod me down as flaimbait or whatever, but I personally think we need a global cataclysm. We don't need something that kills off the entire human population, but we certainly need something to cleanse our planet. We need something to take our collective heads out of our asses and come together as one people and work together for the common good.

do you really think a global cataclysm would make people work together for the common good more than they do today? Or is it more likely that resources would become greatly limited so humans would be more likely to kill each other for their own good? While human life is still a struggle for resources, I doubt the red cross was around in the caveman days, helping the guy who got clubbed on the head and had his dinner stolen.

Re:Flipped a coin?

[Muad'Dave]

So instead of one huge target you could in principle land on, you'd get a swarm of smaller but still deadly rocks that would rain devastation on Earth?

I've always wondered about this. If I have a chunk of rock 1 km in diameter hurtling toward the earth, wouldn't it be better to break it up into small chunks so it would be more likely to burn up in the atmosphere? Even though the mass is the same, the surface area presented to the atmosphere would be greatly increased, which would be much more efficient at ablating away mass and slowing down the incoming pieces (transferring energy to the atmosphere instead of into making a crater).

Where's the trade-off point between distributed death from all the smaller chunks and increased burnup in the atmosphere?