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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."

68 of 284 comments (clear)

  1. Sweet mercy by casio282 · · Score: 4, Funny

    I hope Bruce Willis in onboard.

    --

    :wq
    1. Re:Sweet mercy by raider_red · · Score: 5, Funny

      Good call, but let's leave Ben Affleck on the asteroid this time.

      --
      It's good to use your head, but not as a battering ram.
  2. NO DADDY NO by Anonymous Coward · · Score: 2, Funny

    Can't we just drill 20 miles into it and blow the fucker up with a nuke?

    1. Re:NO DADDY NO by Frank+T.+Lofaro+Jr. · · Score: 4, Insightful

      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!
    2. Re:NO DADDY NO by Matt_R · · Score: 3, Insightful

      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.

    3. Re:NO DADDY NO by 10Ghz · · Score: 2, Insightful
      Now why do special effects people make explosions make noise in a vacuum in sci-fi movies, shows, etc.


      Because it would be stupid without any sound. Go ahead and watch the space-battle-scenes in Star Wars/Trek with sound off if it bothers you so much. You would notice after 5 seconds that it would take about 80% of the coolness away from the battle-scenes.

      Battle of Endor with no sound? Starfleet vs. Borg Cube in First Contact with no sound? Battle-scenes in Babylon 5 with no sound? Maybe it's unrealistic, but I prefer them WITH sound, thankyouverymuch!
      --
      Lesbian Nazi Hookers Abducted by UFOs and Forced Into Weight Loss Programs - -all next week on Town Talk.
    4. Re:NO DADDY NO by Mr.+Underbridge · · Score: 2, Interesting
      Maybe, maybe not. That will only work if the entire body is hard and dense throughout. If any of the material is loose or porous, you'll just compress it a bit.

      Don't believe what you see in movies.

    5. Re:NO DADDY NO by shpoffo · · Score: 2, Funny

      Man, I am so tired of hearing peopel say there is no noise from an explosion in a vaccuum. Have you every HEARD an explosion in outer space? NO, you've never even been there and no one has even SEEN something blow up in outer space - so dont' tell me you *know* it doens't make noise....
       
      .[/joke]
       
      .
      -shpoffo

  3. Crash? by MyLongNickName · · Score: 4, Interesting

    Is this simply a kamikazee run? I did not read anything to make me think otherwise. I seriously question the science of this... being able to calculate the change in direction should only be complicate by not knowing the exact mass of the asteroid.

    I would think something like white paint (using the reflective properties to move the asteroid) would be more interesting. Slower, for sure, but much more effective over a period of months or years.

    Is there something to this mission that I am missing?

    --
    See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
    1. Re:Crash? by republican+gourd · · Score: 5, Insightful

      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.

    2. Re:Crash? by Anonymous+Luddite · · Score: 4, Insightful

      >> 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.

    3. Re:Crash? by Dirtside · · Score: 4, Funny
      I would think something like white paint (using the reflective properties to move the asteroid) would be more interesting.
      Ladies and gentlemen, we have here a person who literally thinks that watching paint dry is more interesting than watching an explosion. Sir, I wish you good luck in finding a circus capable of handling your freakishness.
      --
      "Destroy science and religion. Science would re-emerge exactly the same; but not religion." - Penn Jillette, paraphrased
    4. Re:Crash? by MyLongNickName · · Score: 5, Funny

      ir, I wish you good luck in finding a circus capable of handling your freakishness.

      I have. It is called "Slashdot".

      --
      See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
    5. Re:Crash? by MaskedSlacker · · Score: 2, Interesting

      Haha. Fair enough. Nonetheless my point still stands. The balls in a billiards game follow distinct, verifiable, and most importantly predictable rules. Just because you lack the information to make use of those rules, does not mean the balls behave unpredictably.

    6. Re:Crash? by Profane+MuthaFucka · · Score: 2, Insightful

      Another one: in space, things impacted will spin unless they are hit exactly in line with their center of mass. Your energy intended for deflection might just spin the object up.

      --
      Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
    7. Re:Crash? by Fallus+Shempus · · Score: 2, Interesting

      Whether it is deflected or absorbed greatly affects the outcome
      of the experiment.

      Mainly because they need to know how much energy they need
      to deflect the asteroid, a deflected explosive may need to
      more energetic, where an embeded explosive runs more risk
      of breaking it up.
      They need to know what will happen.

  4. What happens... by Anonymous Coward · · Score: 3, Insightful

    ...if they blow it off course in the wrong direction?

    1. Re:What happens... by MyLongNickName · · Score: 4, Funny

      We all die.

      Seriously, though. If you read the article, you would know that they picked an asteroid that will never cross the earth's path (more than 1AU from sun at all times). The tiny nudge would be like hitting Pavorati with a spit ball. Not nearly enough to make it an earth killer.

      --
      See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
    2. Re:What happens... by ozTravman · · Score: 2, Funny

      Maybe they will conduct scale model tests with Pavorati and spit balls.

    3. Re:What happens... by Tumbleweed · · Score: 2, Funny

      What happens ... if they blow it off course in the wrong direction?

      Multiple answers:

      ALIENS: "Game over, man, game over!"

      LAST STARFIGHTER: *bzzt* "We die."

      YOSEMITE SAM: "Say yer prayers, varmint."

      MARVIN THE MARTIAN: "The Earth? Oh, the Earth will be gone in just a few seconds."

      Do you feel better now?

    4. Re:What happens... by Dirtside · · Score: 3, Funny

      I like the idea, however, that there is something we could hit Pavarotti with that would make him an Earth-killer. Gamma radiation, perhaps?

      "Pavarotti SMASH!!! "

      --
      "Destroy science and religion. Science would re-emerge exactly the same; but not religion." - Penn Jillette, paraphrased
    5. Re:What happens... by RoLi · · Score: 2, Informative
      Is anyone else considering the possibility that this asteroid actually is on a collision course with Earth, and they don't want to panic us? Paranoia hats on, everyone.

      Oh yeah, sure. ESA and NASA keep this collision secret because:

      • They prefer to risk their lifes with a budget-quenching mission rather than make damn sure with 2,3 or more redundant missions.
      • They don't want the funding they would get in face with such a collision

      Also, this is ESA. There isn't nearly as much useless secrecy in Europe than in the USA.

  5. Liv Tyler? by Alex+P+Keaton+in+da · · Score: 4, Insightful

    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
    1. Re:Liv Tyler? by servognome · · Score: 5, Insightful

      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.

      Yeah, like the guy at the water treatment facility - who keeps us from plague, or the fed-ex guy- who transports vital medical supplies, or the building inspector- who ensures our structures don't collapse on us, or the guy who draws those warning pictures - so we don't accidently eat our Shuffles, or telephone sanitizers.

      Astronomers do an important job, but calling them unsung heroes is a little much. If they volunteer to be stuffed in a cannon and shot at the asteroid to deflect its path, then i'd call them heroes.

      --
      D6 63 0D 70 89 81 BB 8E 7B 7C 5F 5D 54 EA AB 73
    2. Re:Liv Tyler? by tgd · · Score: 2, Funny

      OT but if you think building inspectors are the good guys, you've clearly never done any major remodelling.

      Instead of "unsung hero", lets instead call them "territorial demon-spawn".

      And yes, moderators. Thats "insightful" or "funny (in a sad kind of way)" if you've been through that before. "off-topic" if you haven't.

  6. The public will get to view the event by Anonymous Coward · · Score: 5, Funny

    ... but can only watch it in black and white vector graphics, and have to pay $0.25 to view it.

  7. Artist's conceptions of spacecraft by Anonymous Coward · · Score: 4, Funny

    ...are located here. Looks kind of odd.

  8. Dateline 27 September 2159 by DavidRawling · · Score: 5, Funny

    In other news, the asteroid deflected in 2008 by the European Space Agency has been confirmed as hitting Earth in December this year, with an expected impact point near Switzerland.

    It's been nice knowing you folks.

  9. But what about.... by zappepcs · · Score: 4, Funny

    my horoscope... this could immeasurably ruin my life!! Don't these insensitive rock-et science clods know they could end up making it so I never meet a woman?

    1. Re:But what about.... by pseudochaotic · · Score: 2, Funny

      You're so worried about your chances of meeting a woman, you posted to slashdot about it. -_- Right.

      --
      And the l33t shall inherit the 34r7h.
  10. Re:Something wrong with p? by Zaak · · Score: 5, Insightful

    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

  11. Fighting windmills? by ReformedExCon · · Score: 4, Interesting

    Surely they should have chosen a name that implied success rather than invoke the name of a hopeless romantic who is known for fighting the inevitable.

    And they could have spelled it correctly: Don Quixote.

    --
    Jesus saved me from my past. He can save you as well.
    1. Re:Fighting windmills? by Deadstick · · Score: 2, Insightful
      And they could have spelled it correctly: Don Quixote.

      http://www.aache.com/quijote/

      rj

    2. Re:Fighting windmills? by ReformedExCon · · Score: 4, Informative

      That's funny since the original text has it spelled Quixote: http://csdl.tamu.edu/cgi-bin/shuehu/qbrowse/qb?POR C=P&NO=1

      I wonder when they decided to change the spelling.

      --
      Jesus saved me from my past. He can save you as well.
    3. Re:Fighting windmills? by servognome · · Score: 4, Informative

      I wonder when they decided to change the spelling.

      Change from Old Spanish to Modern Spanish. X had the "heh" sound (as in Mexico), but has transitioned to a "sh" sound (as in Ixtacihuatl)/"gs" sound as in explorar. Words have changed to reflect the new usage, but names proper names are blurry, so you will see Mexico, Mejico; Xavier, Javier; Quijote, Quixote

      --
      D6 63 0D 70 89 81 BB 8E 7B 7C 5F 5D 54 EA AB 73
    4. Re:Fighting windmills? by Tarrio · · Score: 2, Informative

      In modern Spanish, the gentleman's name is Don Quijote (the X was pronounced in the same way as J is pronounced now -- that's why Mexico, Texas and Oaxaca are pronounced as "Méjico", "Tejas" and "Oajaca" in Spanish).

      And the reason for the naming is simple: one spacecraft (the Hidalgo -- Don Quijote himself) will ram the asteroid (a windmill) while the other one (Sancho) looks from afar.

    5. Re:Fighting windmills? by Aimak · · Score: 2, Informative
      And they could have spelled it correctly: Don Quixote.

      Excuse me Sir. I think you are mistaking here.

      It's a Spanish book what you are referring to. The mission was conceived by spaniards, and the main contractor is Spanish. They have chosen to use the Spanish spelling: Don Quijote.

  12. In case of slashdotting by Anonymous Coward · · Score: 3, Funny

    The two target candidates are:

    1. 2002 AT4
    2. France

  13. Re:Something wrong with p? by LordRPI · · Score: 3, Funny

    Yeah, unfortunately there is something wrong with that equation. It does not take into account of the direction of which the asteroid will be deflected. Although I hope that the mathematics used to base the "crash" on would be calculated so that it does not shift the objects into a collision course with Earth. Knowing us, some organization will use British units, one will use Metric.

  14. Re:Something wrong with p? by Anonymous Coward · · Score: 2, Insightful

    I think they want to determine how much p of the impactor is needed to change the v of a rock. You see, the important thing is whether the micro-asteroid will stay together or not. Delta p is known in advance, of course!

  15. Whatever happened... by Jeian · · Score: 2, Funny

    ... to that crazy Russian lady who claims that stuff like this will mess up her horoscope?

    1. Re:Whatever happened... by UTPinky · · Score: 2, Funny

      This is part of the settlement... NASA is required to re-adjust her horoscope by deflecting 2 astroids in an opposite direction.

      --
      I'm only paranoid because everyone is against me...
  16. Re:Something wrong with p? by MyGodAreThereNoNickn · · Score: 4, Insightful

    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.

  17. Hmm... But wait... by Pichu0102 · · Score: 2, Interesting

    ...Wouldn't the cost of such a test be well into millions of dollars? That sounds expensive for something that is just a test... But I could be wrong.

    Also, never has the quote at the bottom of the screen been so appropriate.

    Oh, wow! Look at the moon!

    1. Re:Hmm... But wait... by NanoGator · · Score: 2, Funny

      "..Wouldn't the cost of such a test be well into millions of dollars?"

      It costs less than an "Oh shit!" down the road.

      --
      "Derp de derp."
    2. Re:Hmm... But wait... by TheComputerMutt.ca · · Score: 2, Insightful

      I don't see why this was modded funny, it's very serious. Testing like this now is essential if we want to have any reliable ability to do things like this in future.

  18. OOPS by Brad1138 · · Score: 5, Funny

    What we don't want to hear after a successful deflection....

    --
    If you could reason with religious people, there would be no religious people
  19. Brace for impact! by Nom+du+Keyboard · · Score: 3, Funny

    Brace for another lawsuit from that kooky Russian astrologer.

    --
    "It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
  20. I'd deflect her asteroid... by Errandboy+of+Doom · · Score: 2, Funny

    If you're interested in asteroid deflection, Jay Melosh has a few ideas.

    Including: "Deploying a giant parabolic mirror to concentrate the sun's rays and vaporize rock on the surface of the asteroid. The vaporized material flies off at high speed and generates a re-coil action that pushes the asteroid, slowly but surely, in the opposite direction."

    Which is great, because the parabolic mirror can double as a way for Bruce Willis to cook and refrigerate his food while he's there.

  21. Awesome by Liam+Slider · · Score: 2, Insightful

    Great! No really, we need to test out the ability to do this so when we need to do this we can. I hear China also has a planned mission very similar to this. They intent do attempt to change the course of a comet. And we've already demonstrated that we could do such a thing, with Deep Impact (what prompted the Chinese, and likely the ESA as well). True, we didn't change it's course, but if the "object" has been a nuke instead...

    1. Re:Awesome by Nefarious+Wheel · · Score: 2, Interesting
      True, we didn't change it's course, but if the "object" has been a nuke instead...

      It doesn't have to be a nuke. Read "The Moon is a Harsh Mistress" written by an Annapolis grad named Robert Heinlein back in the last century.

      "I don't think we should throw any more rocks at Cheyenne Mountain." " -- Why? " "..It isn't there any more."

      --
      Do not mock my vision of impractical footwear
    2. Re:Awesome by eskayp · · Score: 2, Insightful

      Good to see someone on our planet tending to the immediate threats instead
      of going for more politically productive targets like Mars or the moon.
      Here, in the USA, we haven't even adequately funded the effort to detect
      and track asteroids, let alone deflect or destroy them.
      Until recently amatuer astronomers and a very few dedicated professionals
      have been doing all the heavy lifting, with little or no support from
      our current administration.
      Evidently the people who allocate the funds are too busy starting wars
      and creating tax breaks for their cronies.
      If George Bush would look to the heavens instead of praying to them
      he would find plenty of weapons of mass destruction in earth crossing orbits.

      --
      I didn't desert Windows; Windows deserted me: BSOD
  22. If it hit land, consider ourselves lucky by lightyear4 · · Score: 4, Insightful

    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.

  23. Re:revised standard Don Quixote by Nefarious+Wheel · · Score: 3, Informative
    ...and a whole lot of F's to S's, so children could at least pronounce the words. Haven't you ever done a double-take when you've seen the word "Congrefs" written on a piece of parchment?

    **wax on** It's not an F. What you see is the "long s". It's how they used to draw an S character since the days of Carolingian Minuscule, from which hand our "Times Roman" eventually derived. You'll note there was no crossbar on the letter in that form - the crossbar distinguished the "f" from the "long s". The form we take as "s" appeared only at the end of the word. Thus, "Congrefs" would have been pronounced "Congress". **wax off**

    --
    Do not mock my vision of impractical footwear
  24. I, for one, thank... by Anonymous Coward · · Score: 2, Insightful

    the ESA for showing forethought in a time of chaos. This is the kind of productive stuff that needs to happen.

    We waste so much money on boondoggles (won't even go into that) but so little effort now goes into research into the human condition. We are a smart group, us humans, when we really HAVE to be. Why not try to make it a little more often, just for flip sake, eh?

  25. Re:Something wrong with p? SIMPLE by amdotaku · · Score: 5, Informative

    (p1 + p2)[)[initial]=(p1 + p2)[final]

    Uh, we know the first two p(momentum, vector) values(and that's if we know the mass of the asteroid, which isn't necessarily true), but not the second two. In my math classes, we learned that was 1 equation (vector valued) and two unknown vectors. I don't think anyone can solve that, and no, conservation of kinetic energy won't work because the internal energy changes big time in most non-particle scale collisions. In Mechanics, many of our college educated comrades learned of a way to resolve this textbook documented issue with the simple aide of a constant e, which details the elasticity of the interaction. Unfortunately, e is not easy to determine through theory, and is also just a model (and a bad one at that), and therefore an experiment is usually called for (and usually a lot of them). 'Nuff said.

    http://scienceworld.wolfram.com/physics/Collision. html

  26. Re:Something wrong with p? by Mercano · · Score: 2, Informative

    Someone brought up the Pioneer anomaly over in the Voyager thread earlier today. Intesting stuff, proves Yogi knows what he's talking about.

    --
    #include <signature.h>
  27. Land an anchor on the thing by UnapprovedThought · · Score: 2, Funny
    One craft will impact the asteroid while the other will observe the asteroid before and after the collision

    This sounds a lot like something that's been tried before. Why don't they draw a conclusion from the existing data from Tempel-1? Or, while they're at it, why not try a new concept?

    For instance, how about landing on the asteroid and attaching an anchor to it? Drop anchor (unreel) and wait for the closest approach to the moon. Then, use an ion drive on the anchor to bring it as close to the moon as possible. If the cable is long enough, the anchor will be pulled down into the gravity well of the moon with much greater force than otherwise. It won't capture the asteroid in lunar orbit, but the trajectory of the asteroid will be changed in a far more predictable and adjustable way than with impacts and explosions.

    An extra bonus is that communicating with the anchor, you will always know the exact location of the asteroid.

    The only catch is that you need a very long cable, and that will raise the launch costs.

  28. The grants game by grozzie2 · · Score: 4, Interesting
    This article just goes to show how silly the 'grants game' is when it comes to this type of space mission. The deep impact mission was planned and built when analysis of the rocks was 'in vogue', so it was 'justified' by analyzing ejecta etc from the impact, to determine asteroid composition. Now the ESA boys are contemplating a mission nearly identical, but political times have changed, and 'impacts' is the hot button for getting first priority on grants, so, instead of marking the 'composition analysis' as the primary objective, they mark the 'trajectory change' as the primary objective, and presto, the same mission goes to the top of the heap in the grants pile.

    If you think about this even semi rationally, look at the data from the Deep Impact mission. The trajectory of the rock prior to impact was quite well known, well enough, an intercept course could be plotted and executed. Does anybody think that nobody at nasa thought to measure trajectory AFTER the impact, and possibly calculate trajectory changes of the target rock? This is a mission that cost hundreds of millions of dollars, and that's extremely valuable information, available for the taking after the impact. I'm quite sure that while the primary investigators on Deep Impact are all wrapped up in analyzing ejecta data, there are secondary investigators measuring and calculating trajectory changes.

    The proposed ESA mission is basically Deep Impact Version 2.0, a more refined variant than version 1. Version 1 (executed by Nasa) intended to hit the target rock, and studying ejecta was labelled as the 'primary' objective. In Version 2, the objective is to hit the target rock much more precisely, relabel the 'primary data' as that of the trajectory change, and re-label the ejecta data as 'secondary'. The end result is, a mission plan that hits more political hot buttons (reference the data collection re-labelling), its easier to get grants for impactor related investigation today.

    The reality is, this mission is a logical follow on which builds on the success of Deep Impact. The re-labelling of primary mission goals is just an artifact of the political process required to procure funding, the 'grants game'. The data regarding target object composition will still be collected in various forms, and it'll still get analyzed, just as trajectory data is still being collected and analyzed from the Deep Impact mission.

    1. Re:The grants game by The+Master+Control+P · · Score: 4, Informative

      NASA's Deep Impact mission was against a comet. Because comets continually eject large amounts of gas and dust while they are inside Jupiter orbit, it is not possible to track the comet accurately enough to know what changes in it's course were caused by the impact and what was caused by the gas and dust normally ejected. Indeed, it's impossible to predict the exact path of short-period comets because of this.

      By launching a projectile at an asteroid instead, we will know that any changes in the asteroid's trajectory were caused by our impactor because asteroids are inert and have otherwise very stable and predictable orbits.

  29. Should I Worry? by izomiac · · Score: 3, Interesting

    I'm starting to get worried here. Most of the space programs in the world are trying to hit asteroids, perhaps deflect them. Even the military is now looking at anti-satellite weapons. So I'm beginning to wonder, what's with this sudden surge of interest in defense against things hitting us from space? Do they know something (troubling) that I don't?

    1. Re:Should I Worry? by trongey · · Score: 2, Funny

      ...Do they know something (troubling) that I don't?

      I suspect they know a lot of things that you don't. Things that you would find very troubling.

      --
      You never really know how close to the edge you can go until you fall off.
  30. Re:Something wrong with p? by ScriptedReplay · · Score: 3, Interesting

    Good old linear momentum conservation is insufficient information to specify the outcome. Throw in energy balance (assuming you account for all losses of kinetic energy properly) and you have enough information for 1D collisions only - still not enough equations to determine angles; now moving to 'real life' you have to add angular momentum conservation to the mix, too. To completely specify the answer you need details about geometry (mass center, impact point) and surface (orientation, hardness and so on) This already moves the question quite a bit into engineering - and requires data on asteroids. I assume gathering such data is closer to the purpose of this experiment.

  31. Re:Now... by shadowmas · · Score: 3, Funny

    i wonder what effect this will have on my horoscope ;)

  32. Re:Careful! by vlachen · · Score: 2, Insightful

    That's it.

    You're all cut off.

    No more! No more I say!

    How many "what if they knock it on course to hit Earth" lines does a person have to read around here.

    For the sake of sanity, STOP!

    --
    Vlachen of Aranias
    Freelance Slacker
    Jack of All Trades
  33. Alien Attack! by mtjs · · Score: 2, Funny

    We will deflect an Asteroid. Within a few 1000 years it will hit another world. The few aliens that 'went underground' will figure out why that happend and they will launch an attact om earth...

  34. Crashing spacecraft into celestial bodies? by zootm · · Score: 2, Funny

    There's a Beagle 2 joke here somewhere, but I can't place it.

  35. What about the little people... by waamaral · · Score: 2, Funny

    ...who live in the asteroid? I wonder if they have the technology to build a rocket to deflect the two metal asteroids in crash-route with them.

    --
    What, do I need a sig now?