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3 Former Astronauts: Earth-Asteroid Collisions Are a Real But Preventable Danger

Three former astronauts — Ed Lu, Tom Jones, and Bill Anders — say that reassuring figures about the rarity of asteroid collisions with Earth are perhaps too reassuring. The B612 Foundation, of which Lu is a director, has been established to draw public awareness to the risks of a large asteroid hitting a population center -- which these three men say is a far more serious public danger than has been acknowledged by NASA and other agencies. And beyond awareness, the Foundation's immediate goal is to raise money to " design and build an asteroid-finding space telescope and launch it by 2017," and then, Armageddon-style, to follow that up with technology to divert any asteroids whose path would threaten earth.

71 comments

  1. give each citizen a laser cannon by Anonymous Coward · · Score: 0

    made by a 3d printer & glued to the back of our pickup trucks. asteroid season would be year round.... wake up look up our greatest enemy remains us. the odds of taking ourselves out are much higher than creation would allow? so some intervention is likely not going to be violent but more of a (r)evolutionary good nature

    1. Re:give each citizen a laser cannon by Livius · · Score: 1

      But we don't have 3-D printers that can make sharks yet.

  2. Well, technically by ScudBee · · Score: 2

    no one can be called "astronaut" unless they travelled to another star system

    1. Re:Well, technically by The+Grim+Reefer · · Score: 1

      no one can be called "astronaut" unless they travelled to another star system

      Well the Russians really set the bar high then, didn't they?

  3. I am all for this research by mysidia · · Score: 0

    This could save billions of people. And it's one kind of threat -- that in principle: we should be able to see coming, if we are just looking

    We could also do well to have solar flare early warning and harden the power grid against the next Carrington event; which is overdue and expected every couple hundred years.

    However.... what happens when there is an Asteroid that will threaten earth... in between the time the telescope is developed, but before the asteroid diversion tech is developed?

    1. Re:I am all for this research by Charliemopps · · Score: 1

      However.... what happens when there is an Asteroid that will threaten earth... in between the time the telescope is developed,
      but before the asteroid diversion tech is developed?

      We already have the tech to deflect an asteroid (depending on its size) Building the device however, wold require a huge investment. I suspect that once we detected an asteroid on a course that would collide with earth, it would be pretty easy for the US or Russia to just declare a state of emergency and build what was needed in a few months. Perhaps by then India and China will have space programs robust enough to assist as well.

    2. Re:I am all for this research by fuzzyfuzzyfungus · · Score: 2

      However.... what happens when there is an Asteroid that will threaten earth... in between the time the telescope is developed, but before the asteroid diversion tech is developed?

      Well, probably the de-facto legalization of every drug ever, along with cataclysmic declines in production in all sectors where working kind of sucks...

    3. Re:I am all for this research by pixelpusher220 · · Score: 1

      the tech required is nothing more than gravity. Park a multi-ton spacecraft just behind (or in front) of the asteroid and it will take care of the problem. (obvious technical details left to the reader)

      --
      People in cars cause accidents....accidents in cars cause people :-D
    4. Re:I am all for this research by LordLimecat · · Score: 3, Insightful

      Im not sure if youre serious.

      A multi-ton object would not have any appreciable gravitational pull. The largest man-made objects ever created do not create an appreciable gravitational field. Using the calculator here:
      http://astro.unl.edu/classacti...
      An asteroid with a mass of 4*10^18kg at a distance of 1km from a Saturn 5 rocket fully loaded (Mass of 4 * 10^7kg) would feel an acceleration of 0.000000001 m/s^2, and would accelerate the rocket at a rate 10 orders of magnitude higher. The only noticeable effect would be the rocket being pulled into the asteroid, barely altering its course before joining it.

      That completely ignores how insanely expensive even that minuscule experiment would be.

    5. Re:I am all for this research by Anonymous Coward · · Score: 0

      So by your numbers the gravity of ~ 14 Saturn 5s acting for one year
      will deflect your 80km(?) mass by one Earth radius

      Doesn't sound impossible.

      Got a better plan?

    6. Re:I am all for this research by Anonymous Coward · · Score: 0

      insanely expensive?

      in terms of a fictional measurement of 'value' of man hours to society

      how much is the real value to society are the current highly skilled people dedicating their lives to making you click an advert..... it's just monopoly money.

    7. Re:I am all for this research by Anonymous Coward · · Score: 0

      Doesn't sound impossible.

      The idea of 14 Saturn V rockets burning continuously for one year without the means to refuel* doesn't sound impossible?

      Got a better plan?

      Unfortunately, no. But I think having no plan is better than having a bad plan. Having a bad plan gives people a false sense of security. Having no plan forces people to think about the problem.

      *If that isn't what you mean by "acting for one year", then please explain what was meant.

    8. Re:I am all for this research by Hognoxious · · Score: 2

      what happens when there is an Asteroid that will threaten earth... in between the time the telescope is developed, but before the asteroid diversion tech is developed?

      I'm not an astrophysicist, but my best guess is that it'll hit us.

      --
      Confucius say, "Find worm in apple - bad. Find half a worm - worse."
    9. Re:I am all for this research by TheTurtlesMoves · · Score: 1

      We could also do well to have solar flare early warning and harden the power grid against the next Carrington event; which is overdue and expected every couple hundred years.

      That is not how it works. Just because you haven't won lotto for the last 100 years does not make you more likely to win lotto this week because your "overdue".

      If the chance of it happening is .5% per year, then it not happening for 200 years means the probability of the event next year is *still .5%*.

      --
      The Grey Goo disaster happened 3 billion years ago. This rock is covered in self replicating machines!
    10. Re:I am all for this research by Sqr(twg) · · Score: 2

      This is called a gravity tractor, and researchers do consider it seriously.

      0.000000001 m/s^2 is approximately 0.15 earth radii per year squared.

    11. Re:I am all for this research by Anonymous Coward · · Score: 0

      Sorry I misunderstood what you were suggesting.

      Let me rephrase that.

      Your scenerio is totally unreal. For those numbers I get densities
      a couple hundred times that of lead.

      Regardless of how you apply the force you'll need something like
      4E5kg/s of reaction mass for realistic exhaust velocities (100km/s)

    12. Re:I am all for this research by Anonymous Coward · · Score: 0

      oops should have been 4E4kg/s

    13. Re:I am all for this research by pixelpusher220 · · Score: 2

      As another responder said, this concept is known as a gravity tractor.

      I did say obvious technical details were still needed. You can't just park something small close to a big object; as you say the small object will be affected much more an simply be pulled in. However, since the gravitational attraction is fairly small, as you note, even a small ion engine can push enough to counter it. Since IOM engines can run for decades on a few pounds of fuel, you aim them at 45 degree angles (so as not to push the asteroid) and poof, the asteroid is pulled towards the space craft - slowly and over a long time, but it is pulled and a little is all you need.

      It's not something you can do if you discover an asteroid that will impact in less than a year, this requires time as the effect isn't huge. However, a small effect over 3, 5 or 10 years is plenty to slow down or speed up the asteroid such that it will miss us. You only have to make it get to the time and place of intersection with earth a day or even a few hours later or earlier and the problem is solved.

      If we discover an asteroid coming in 6 months, we're basically screwed. There is no Armageddon Movie answer that fixes it.

      --
      People in cars cause accidents....accidents in cars cause people :-D
    14. Re:I am all for this research by mysidia · · Score: 2

      If the chance of it happening is .5% per year, then it not happening for 200 years means the probability of the event next year is *still .5%*.

      No. That's not true. That requires making an unwarranted assumption of independence. You are assuming that the passage of time is independent w.r.t. the solar activity.

      You are essentially assuming is true that is something already known to be totally false.

      Just because you haven't won lotto for the last 100 years does not make you more likely to win lotto this week because your "overdue".

      A carrington event is not a lottery win.

      Astrological events are cyclical.

      There is not a probability that this event will happen selected by random chance. It's essentially certainty that this event will happen.

    15. Re:I am all for this research by TheTurtlesMoves · · Score: 1

      Wrong. Don't pass go don't collect $200. Sure solar activity follows an 11 year cycle. But that simply means that the probability changes over that 11 years.. a bit. But not much. Its like having a 11 year cycle on how many lotto tickets you buy. Still does not make these events overdue.

      The sun does not sit there and go "haven't sent a big flare in the direction of earth for 30 years.. better do one now". The chance of one in the next 11 years is no different from the last 11 years. Yea i have a masters in Astrophysics. Yes this is what the Scientist say. Not some uninformed /. who clearly knows nothing about statistics or the physics behind them.

      --
      The Grey Goo disaster happened 3 billion years ago. This rock is covered in self replicating machines!
    16. Re:I am all for this research by LordLimecat · · Score: 1

      Youre forgetting about the 3m/s^2 acceleration that the asteroid is applying to the load.

      Either your rocket slams into the asteroid, ending the gravity tractor, or you need to pump an incredible amount of energy into the rocket to keep it at a distance. Since when do Saturn Vs have sufficient fuel to fire for a year straight?

    17. Re:I am all for this research by Sqr(twg) · · Score: 1

      Just like the moon is going to crash into the Earth unless we pump an incredible amount of energy into it to keep it at a distance?

      (Read the Wikipedia article I linked to, if you want to know the details.)

    18. Re:I am all for this research by RockDoctor · · Score: 1

      Since when do Saturn Vs have sufficient fuel to fire for a year straight?

      Since when did anyone (other than you) suggest using Saturn Vs for a job like this?

      For a long term job like this, you'd be looking at an ion drive powered by a solar panel array, which is strong enough to counteract the gravitational attraction of the tractor-ship to the asteroid. Produce a few kilogrammes of thrust for the several years necessary ; re-supply with Xenon (probably) with an automated ship as necessary. Redundant ion drives (3 or 5, or more) arranged so that the exhaust doesn't impinge on the asteroid surface.

      Seriously, the designs for doing this have been discussed on here (and in more serious fora) multiple times in the last decade. Have you missed all of them?

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
    19. Re:I am all for this research by RockDoctor · · Score: 1

      There is not a probability that this event will happen selected by random chance. It's essentially certainty that this event will happen.

      In the same way, a Boltzmann Brain is also nearly a statistical certainty. OK - their probability is only like 10^-100 per year, but since the future has an essentially unlimited number of years, then the average lifeform in the universe is a Boltzmann Brain.

      If you agree that one event in 200 years of observations gives us an estimated probability of 0.5% events per year, then yes, it is true that in a period of some thousands of years such an event becomes essentially a certainty. But the probability remains at 0.5% per year.

      Yes, that is assuming that Carrington events are independent of each other. Which is an hypothesis that we have NO evidence against. It would not be surprising if it turned out that Carrington Events are more common at Solar Maximum (for example), but with a sample of ONE event, we don't know how they're distributed w.r.t. the solar cycle.

      What we do know is that in approximately 15 solar cycles, we've seen approximately one Carrington event. So that's an average of about 0.067 Carrington events per solar cycle. Same rate, different scale.

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
    20. Re:I am all for this research by mysidia · · Score: 1

      Wrong. Don't pass go don't collect $200. Sure solar activity follows an 11 year cycle. But that simply means that the probability changes over that 11 years.. a bit. But not much.

      Sounds like you're just bullshitting your way through this.

      The de Vries solar cycle is approximately 205 years. Your argument that relies on statistical independence and a reasonably uniform probability distribution does not hold any water.

    21. Re:I am all for this research by tragedy · · Score: 1

      The Moon may not be a good example because it does extract energy from the Earth (from its rotation via tidal forces) so that its orbital distance is actually increasing over time. Not arguing agains the gravity tractor, just saying that maybe wasn't the best example.

  4. Tom Jones says by Anonymous Coward · · Score: 0

    It's not unusual to be under threat of asteroid collision.

    1. Re:Tom Jones says by Marxist+Hacker+42 · · Score: 1

      Ground Control to Major Tom...

      --
      SJW: a person who perceives an injustice, and while correcting it, commits a greater injustice.
    2. Re:Tom Jones says by pixelpusher220 · · Score: 1

      more like "Major Tom to Ground Contro?" (which just got wiped out by an asteroid!)

      --
      People in cars cause accidents....accidents in cars cause people :-D
  5. Astronouts are experts? by OneAhead · · Score: 3, Insightful

    I'm not saying these guys don't have a valid point, but why is something important because an astronaut says it? Aren't astronauts usually pilots who received advanced training for going to space? How does their word carry more weight than scientists or analysts who have studied the subject their whole life? Again, their point may or may not be valid, but this is the kind of stuff that belongs in a Sunday newspaper. For "news for nerds", I at least expect an article in Scientific American.

    1. Re:Astronouts are experts? by Anonymous Coward · · Score: 1

      I at least expect someone who's going to put this kind of question out there to do a little research. Beyond simply being in the industry that will likely tackle these questions each one of these guys sports a formal education that 99.998% of Slashdotters will never achieve. And yes, at least two of the three are extremely pertinent to the question at hand and the third would have insights into the technical aspects of some of the potential solutions.

    2. Re:Astronouts are experts? by beelsebob · · Score: 1

      Why do they need to be experts? Who said that it was because they were astronauts that we should believe them, and not because they have a valid point?

    3. Re:Astronouts are experts? by Anonymous Coward · · Score: 0

      Why do they need to be experts?

      Because otherwise their opinion is just that, an opinion. They're free to have whatever opinion they want, but decisions must be left to the experts.

      Who said that it was because they were astronauts that we should believe them, and not because they have a valid point?

      The title of the article. There's no way to know if their point is valid, but unless the scientific community says there is chances are there isn't. To me it seems like a waste of money, but so is having thousands of nukes.

    4. Re:Astronouts are experts? by wonkey_monkey · · Score: 5, Informative

      but why is something important because an astronaut says it?

      As the summary points out, Ed Lu isn't just "an astronaut." He's a director of the B612 foundation. This aren't just three guys who used to work in space, recently got drunk in a bar and decided someone should do something about all these asteroids they keep hearing about on the news.

      Aren't astronauts usually pilots who received advanced training for going to space?

      No. Ed Lu is a physicist (and was one before he became an astronaut), and Tom Jones was working on remote sensing of asteroids before he became an astronaut.

      --
      systemd is Roko's Basilisk.
    5. Re:Astronouts are experts? by ensignyu · · Score: 3, Informative

      Not all astronauts are trained as pilots; these days, a lot of them have scientific background. In this case, Ed Lu is a former astronaut who studied physics and published key papers about using a gravity tractor to deflect asteroids.

    6. Re:Astronouts are experts? by Anonymous Coward · · Score: 4, Insightful

      Ed Lu has a PhD in applied physics from Stanford. Tom Jones has a PhD in planetary science. Bill Anders has a masters in nuclear engineering.
       
      I think you need to get your head out of your ass.

    7. Re:Astronouts are experts? by wonkey_monkey · · Score: 1

      well, hell yeah, the astronaut who didn't even get a C- in astrophysics

      Who's that then?

      --
      systemd is Roko's Basilisk.
    8. Re:Astronouts are experts? by Anonymous Coward · · Score: 0

      Even if they were "just" trained as pilots, a military pilot has to have the equivalent of a technical degree anyway.

    9. Re:Astronouts are experts? by jpellino · · Score: 1

      I think when your life can end without warning from one of these the size of a pea, you have at least a bit more insight and concern than the average citizen. As Chris Hadfield has quipped, you spend your time as an astronaut with at least a bit of your brain constantly reviewing "What's the next thing that can kill me.?"

      --
      "Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
    10. Re:Astronouts are experts? by OneAhead · · Score: 1

      Perhaps I should have phrased that more carefully. No, being astronauts doesn't preclude them from having a valid point, as I said myself. It does, however, put a little bit more burden of proof on them than if it were an expert making the same claims. All they have so far is: "We will (in the future) present data (nobody else has) that shows that all the experts are wrong and that you should give us money." Now, I don't know about you, but that's enough to drive my scam-o-meter straight into the red. No matter whether you're talking infinite-dilution homeopathy, cold fusion, or a certain probiotics company that has recently been flooding the internet with claims that the US is suffering a debilitation candidiasis epidemic, the playbook is always the same.

      Tomorrow, they will give their presentation. If the experts don't tear them to shreds is the days after, then and only then you will have a story worth posting on slashdot.

    11. Re:Astronouts are experts? by Anonymous Coward · · Score: 0

      soo... Leonerd Raj and Wolowitz

  6. The ability to deflect asteroids == a strike by Anonymous Coward · · Score: 1

    If you can move the bastards, you can use them as weapons.

    1. Re:The ability to deflect asteroids == a strike by jsepeta · · Score: 1

      we'll just divert asteroids from NYC to Beijing.

      --
      Remember kids, if you're not paying for the service, YOU ARE THE PRODUCT THAT IS BEING SOLD.
    2. Re:The ability to deflect asteroids == a strike by mark-t · · Score: 1

      Against what? Other habitable planets?

  7. KSP ARM by OptimalCynic · · Score: 3, Insightful

    No need to worry, we're busy training up the populace with the Asteroid patch to Kerbal Space Program.

  8. the bugs in Starship Troopers diverted them by turkeydance · · Score: 0

    the references never die! everyone fights. no one quits.

  9. Governance could be a problem... by fuzzyfuzzyfungus · · Score: 3, Insightful

    Aside from the technical difficulties (which are certainly real; but probably surmountable with time and funding), I would be concerned about the political side of the project(politics being...somewhat less of a solved problem... than space and blowing things up).

    The technology sufficient to divert an asteroid, especially with limited warning(which precludes some of the subtler 'attach an ion drive or give it a slow shove with a laser' type schemes), is probably pretty punchy, possibly 'basically an ICBM but better at escaping earth's gravity well' punchy. It would be an unfortunate irony if, in the attempt to mitigate the city-destroying-asteroid threat, we ended up with some sort of proliferation problem or another round of delightful nuclear brinksmanship.

    In an ideal world, you'd hope that people could put "Stopping asteroid apocalypse" in the category of 'things more important than your petty nation-states and dumb ethnic and religious squabbles'; but I wouldn't exactly be shocked if people largely can't and every stage of an anti-asteroid project ends up being a bunch of delicate diplomacy and jingoistic dickwaving between the assorted nuclear powers, along with a lot of hand-wringing about anti-satellite capabilities, and generally a gigantic mess.

    1. Re:Governance could be a problem... by dkf · · Score: 2

      The technology sufficient to divert an asteroid, especially with limited warning(which precludes some of the subtler 'attach an ion drive or give it a slow shove with a laser' type schemes), is probably pretty punchy, possibly 'basically an ICBM but better at escaping earth's gravity well' punchy.

      Not if you detect it far enough out. If you've got plenty of time, even a small force (e.g., from laser ablation) is quite enough to divert an asteroid well away from the Earth; it's amazing what a small force applied over a long time can do, especially if you've got negligible friction.

      --
      "Little does he know, but there is no 'I' in 'Idiot'!"
    2. Re:Governance could be a problem... by Anonymous Coward · · Score: 0

      If you have the capability to divert an asteroid to not hit earth, you also necessarily have the ability to divert one to fall on people you don't like. Most asteroid impacts make nuclear weapons look like firecrackers.

      Whoever holds the high orbit rules the world.

  10. Most important priority? by Anonymous Coward · · Score: 1

    Perhaps hardening our power grid against Carrington events would be a better use of money. That shouldn't preclude working on the asteroid problem concurrently, but I would put a higher priority on dealing with CMEs, which are far more likely to threaten humanity on a large scale.

    1. Re:Most important priority? by Anonymous Coward · · Score: 0

      Ummm, i think diverting money to another project pretty much PRECLUDES the use of that money for fighting asteroids. BUT, you did say concurrently, so your obviously a democrat. Or a republican.
      Either way, we die with you in charge, whether an asteroid hits us or not.

  11. Nuke it from the ground by K.+S.+Kyosuke · · Score: 0

    It's the only way to be sure.

    --
    Ezekiel 23:20
  12. science fiction... by confused+one · · Score: 3, Insightful

    Most science fiction says it happens this way:

    After the asteroid impact... Humanity pulled itself from the breach of collapse and rebuilt. Once they could regain a foothold on space, they made it a priority to put in place the necessary resources to make sure it would never happen again.

    OK, so, while it is fiction, sometimes literature provides insight into the human psyche. Frankly, I doubt you'll be able to convince the world governments to put any real money into an asteroid defense venture... that is until an impact happens and does sufficient damage to wake up all the people in power up. Most think that it will never happen. Most also believe they have more important issues to deal with in their local district and can't concern themselves with global issues.

  13. Arkyd are already doing this. by andrewla · · Score: 3, Informative

    The Arkyd project by Planetary Resources has already raised $ 1,505,366 on Kickstarter to put telescopes in orbit to detect asteroids.
    https://www.kickstarter.com/pr...

    Lets hope everybody shares the same open source database.

  14. Color me a "skeptic" by bunratty · · Score: 4, Insightful

    Earth has been impacted by asteroids in the past, so there's nothing to worry about. It's just a natural phenomenon. Besides, the people saying we should be looking for asteroids are just greedy for grant money. If it turns out the be a real threat, I'm sure the technology to deal with it will magically appear -- with the economy the way it is we can't afford nonessential projects now.

    Remember how silly these arguments sound when applied to other potential problems.

    --
    What a fool believes, he sees, no wise man has the power to reason away.
    1. Re:Color me a "skeptic" by Anonymous Coward · · Score: 1

      Yeah, no problems!

      If the higher mammals like humans get wiped out, sooner or later something else will evolve to take their place...

    2. Re:Color me a "skeptic" by sexconker · · Score: 0

      Earth has been impacted by asteroids in the past, so there's nothing to worry about. It's just a natural phenomenon. Besides, the people saying we should be looking for asteroids are just greedy for grant money. If it turns out the be a real threat, I'm sure the technology to deal with it will magically appear -- with the economy the way it is we can't afford nonessential projects now.

      Remember how silly these arguments sound when applied to other potential problems.

      You're trying really hard, but all of those sarcastic points are 100% correct.
      Impacts are nothing new. Impacts are not an immediate threat. People ARE looking for grant money we can't really afford, and if there is a serious threat the technology WILL magically appear when the US, China, and Russia are forced to bring out their secret military toys. Spending money now on projects that likely have a lot of overlap with existing (secret) tech already in use by certain governments IS a waste.

    3. Re:Color me a "skeptic" by Anonymous Coward · · Score: 0

      if there is a serious threat the technology WILL magically appear when the US, China, and Russia are forced to bring out their secret military toys.

      The technology existed fifry years ago; MIT did a serious study of how to deflect Icarus if it should be on a collision course with Earth, using a bunch of nukes launched on Saturn Vs. We could do better with modern technology, except... oops... we don't have any rockets big enough to launch them on. Falcon 9 Heavy might be usable in a few years.

    4. Re:Color me a "skeptic" by Tablizer · · Score: 2

      Earth has been impacted by asteroids in the past, so there's nothing to worry about. It's just a natural phenomenon

      ^ Cockroach lobbyist

    5. Re:Color me a "skeptic" by Anonymous Coward · · Score: 0

      Earth has been impacted by asteroids in the past, so there's nothing to worry about.
      That's what the dinosaurs used to say to themselves!

  15. There is nothing else the planet. by Anonymous Coward · · Score: 1

    Should be working on. Except stopping these.

  16. Maybe it's the weightlessness by PopeRatzo · · Score: 1

    Your having been to space is no guarantee that you're not crap-on-the-floor looney.

    I would have thought that we've learned better than to pay too much attention to former astronauts. They might well be right about the asteroids, but I still think we should go ahead and get a second opinion on this.

    --
    You are welcome on my lawn.
  17. Translation : We need a new gig, how about this ? by Anonymous Coward · · Score: 0

    Frankly the earth could use a few billion lopped off the current
    population, and I would welcome an asteroid if it will accomplish
    this, even if it means I am among those who die.

  18. Re:Translation : We need a new gig, how about this by flyingfsck · · Score: 2

    People die all the time. It is not necessary to kill people in a war or otherwise, to reduce the population. All that is needed is contraception.

    --
    Excuse me, but please get off my Pennisetum Clandestinum, eh!
  19. Ah yes, planet "nothing else", a fool's paradise. by VortexCortex · · Score: 4, Interesting

    There is nothing else the planet. Should be working on. Except stopping these.

    Yes there is. Self sustaining off-world colonies AND asteroid deflection technologies go hand in hand to help fight extinction -- which should be priority #1 for any truly sentient race.

    Clearly asteroids are a very real threat, and I black-hole heartedly agree with the notion that Earth's space agencies are not giving them the level of public concern these threats should have: Humans are currently blind as moles to space. Any statement to the contrary is merely shrouding the issue in the Emperor's New Clothes. Earth's telescopes can study very small parts of space in some detail, but do not have the coverage required to make the dismissive claims that NASA and other agencies do about asteroid impact likelihood -- note that they frequently engage in panic mitigation. Remember that asteroid transit NASA was hyped about, meanwhile another asteroid whipped by completely unexpectedly closer than your moon, too late to do anything about? Remember Chelyabinsk? That one was 20 to 30 times Hiroshima's nuclear bomb, but it didn't strike ground. What kind of wake-up call is it going to take?! You'd probably just get more complacent even if an overly emotional alien commander committed career suicide in the desert to take your leaders the message that Earth was surely doomed without a massive protective space presence -- If such a thing ever occurred, that is.

    Seriously, the space agencies are essentially lying by omission to the public by not pointing out the HUGE error bars in their asteroid risk estimates. I mean, Eris, a Dwarf Planet, was only discovered in 2005! Eris is about 27% more massive than Pluto, and passes closer in its elliptical orbit than Pluto -- almost all the way in to Neptune! Eris is essentially why your scientists don't call Pluto a planet anymore. They deemed it better to demote Pluto than admit you couldn't see a whole planet sitting right in your backyard... And NASA expects you to believe their overly optimistic estimates about far smaller and harder to spot civilization ending asteroids? Eventually your governments won't have the luxury of pissing away funding via scaremongering up war-pork and ignoring the actual threats you face, like a bunch of bratty rich kids.

    Asteroids are only one threat, and one that we could mitigate relatively easily given advanced notice of their trajectories. However, Coronal mass ejections, Gamma ray bursts, Super Volcanoes, Magnetosphere Instability, etc. are all also severe threats that humanity can't mitigate with telescopes and a game of asteroid billiards alone -- Though fast acting manipulation of the gravitational matrix via strategic placement of asteroids could help with CMEs or gamma bursts too once you had a sufficient armament of even primitive orbiting projectiles. The irregularity in your magnetosphere should be particularly distressing because it is over 500,000 years overdue to falter and rebuild as the poles flip (according to reconstructions of your geo-magnetic strata) -- It could go at any time! Given the current very abnormal mag-field behavior you have no idea if it will spring right back up nice and organized like or leave you vulnerable to cosmic rays and solar flares for a few decades or centuries.

    You should be grateful that the vulnerable periods of mag-pole flops halted as soon as humanity began showing some signs of intelligence -- even if this is absolutely only a mere coincidence. Mastery of energy threats will remain far beyond your technological grasp for the foreseeable future, but your species can mitigate such threats of extinction by self sustaining off-world colonization efforts! In addition to getting some of your eggs out of this one basket, the technology to survive without a magnetosphere on the Moon and Mars could be used to save the world here on Earth. In the event of a worst case scenario, humans could then repopulate Earth all by themselves

  20. defined by Anonymous Coward · · Score: 1

    astronaut
    astrnôt/
    noun
    noun: astronaut; plural noun: astronauts

            1.
            a person who is trained to travel in a spacecraft.

  21. Planetary Resources and Laserbees by werepants · · Score: 1

    First of all, Planetary Resources seems to be devoting some significant effort to this and already has significant investment and development underway... mind you, their focus is on asteroid resource utilization, but they are still ultimately tracking asteroids and learning how to manipulate and relocate them. The fact that these are the exact same capabilities required to prevent an asteroid impact is not a coincidence.

    The second thing is the Planetary Society's Laserbees concept - get a fleet of tiny, solar-powered satellites with frickin' lasers, send them to orbit around an asteroid of interest, and then have them fire their lasers at the asteroid, timed such that they keep hitting the proper point, the asteroid heats up and ejects mass in the direction of your choosing, and you basically have a laser-powered thruster that uses solar power and the asteroid itself as reaction mass.

    This concept has been reviewed in depth and compared very favorably with other suggestions, and actually holds some promise of scaling well, unlike the gravity tractor technology.