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ESA Selects Targets for Asteroid Deflection Test
Vandil X writes "The European Space Agency has announced that it has selected two candidate asteroid targets for a planned mission to impact an asteroid in an attempt to deflect the asteroid off course by a measurable amount. The mission, dubbed "Don Quijote," will send two spacecraft to their final choice asteroid. One craft will impact the asteroid while the other will observe the asteroid before and after the collision. The mission craft and target selection are expected to be finalized sometime in 2007."
...if they blow it off course in the wrong direction?
I'll go if Liv Tyler is waiting upon my return (although when I get back she will be a bit old).
FTA: On 19 December 2004 MN4, an asteroid of about 400 m, lost since its discovery six months earlier, was observed again and its orbit was computed. It immediately became clear that the chances that it could hit the Earth during a close encounter in 2029 were unusually high. As the days passed the probability did not decrease and the asteroid became notorious for surpassing all previous records in the Torino and Palermo impact risk scales - scales that measure the risk of an asteroid impact just as the Richter scale quantifies the size of an earthquake.
It is funny what we never think of- every night while we sleep there are so many people keeping us safe- Call me a geek, but astronomers are unsung heroes. I am glad someone is worried about destruction of the Earth...
And All I Ask is a Tall Ship And a Star to Steer Her By
What's wrong with the good old p=mv (momentum)?
"In theory there is no difference between theory and practice. In practice there is."
-- Yogi Berra
TTFN
Yes, the possible deflection of an object of a given mass and velocity when struck with another object can be calculated. But you miss lots of other important information if you ignore real world tests. Just off the top of my head:
1) You assume that the target object is solid enough to resist being broken into multiple pieces. It does no good to deflect a small chunk of the object while the main mass continues on its normal course.
2) If you are planning on hitting an object enough to deflect it, you need... a bit of practice. The targetting, propulsion and all other such systems are just as big a part of this test as anything else. All the mathematics in the world won't help you play pool with a bad cue.
3) Is a collision with an asteroid likely to be elastic? Will the striking object bounce off of the target or embed itself within it? These are very different models as far as where the force goes.
4) As a side effect, you get more information along the lines of the previous Deep Impact probe.
>> We are dealing with very simple physics here.
You've never played nine-ball for money have you? Banging one object into another doesn't always have predictable results.
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I haven't RTFA, but I expect that they aren't looking to challenge the laws of physics as much as test their engineering skills. It's pretty hard to hit something that far away and going that fast, especially if you want to hit it a particular way. They are probably testing to see if they can hit it just the way they want to so that they can actually make use of p=mv.
If it were to impact a landmass, we could consider ourselves lucky. Given the high proportion of water to land on the planet, the odds are overwhelmingly against a land impact. Sure, it happens. Sure, it would suck. A land impact would undoubtedly render complete destruction over a large area, alter local climate, cause all fault-lines to shatter, and reduce the affected area to glowing slag. However, that IS the good news. Now the bad news: Models of an ocean impact suggest the global climate would be upset for decades - if not longer. It would impose near ice-age conditions due to solar energy reflected by the planet-wide clouds caused by the vaporization of several trillion tons of seawater. Muddy, salty rain would destroy the world's breadbaskets. Sunlight might not reach the surface for tens of years.
..The implications are enormous, and need not be enumerated; surely the point is made.
Actions such as these aimed at researching the feasibility of deflection should be supported, not something due scorn. The odds of such a cataclysm occurring in our lifetime are indeed negligible...but surely, being prepared is better than being caught with our pants down.
Alarmist? Maybe; the course of history will judge.
Umm, you're kidding, right?
Nuclear bombs will work fine in a vacuum. They don't need oxygen or anything else to support combustion, because they don't use combustion - they use a NUCLEAR (imagine that!) reaction, not a chemical one. The high explosive used to fire the nuke I don't believe needs O2 either, and if it did, that would be an easy problem to deal with.
Yeah, no one will hear the explosion, but that isn't a problem.
Now why do special effects people make explosions make noise in a vacuum in sci-fi movies, shows, etc.
We KNOW better than that, well most of us anyway.
Just because it CAN be done, doesn't mean it should!
So since they drilled down into the rock, the medium density should be really high, yeah?
Sure nukes in open space is questionable, but the AC was talking about placing the nuke within the asteroid - Armageddon style.