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Can NASA Protect Earth from Catastrophic Asteroid Collisions? (scientificamerican.com)

An anonymous reader quotes Qz: NASA is not going to be able to find all the asteroids big enough to cause serious devastation on Earth by 2020 -- or even 2033. Also: For a hypothetical attempt to send a spacecraft to divert an seriously dangerous incoming asteroid, we'll need a ten year heads-up to build it and get it to the asteroid.

The good news? They're working on it. "If a real threat does arise, we are prepared to pull together the information about what options might work and provide that information to decision-makers," Lindley Johnson, NASA's Planetary Defense Officer, told reporters.

But NASA's methodology is now being criticized by former Microsoft CTO Nathan Myhrvold -- in the peer-reviewed journal Icarus. An anonymous reader quotes Scientific American: Since 2016, Nathan Myhrvold has argued that there are fatal flaws in the data from NASA's NEOWISE mission to hunt space rocks... NASA is working to develop a follow-up space telescope that would use the same scientific approach to fulfill a mandate from the US Congress to discover nearly all of the space rocks that could pose a threat to Earth.

After 18 months of peer review, and plenty of acrimony on both sides, Myhrvold's latest critique appeared on 22 May on the website of the journal Icarus. Among other things, he argues that NEOWISE estimates of asteroid diameters should not be trusted -- a crucial challenge, because the size of an asteroid determines how much damage it would cause if it hit Earth. "These observations are the best we're going to have for a very long time," says Myhrvold. "And they weren't really analysed very well at all."

NASA hasn't responded in detail to Myhrvold's criticism, though a June 14th statement said their team "stands by its data and scientific findings," noting that they'd also been published in several peer-reviewed journals.

51 of 92 comments (clear)

  1. /. seems on a mission to prove Betteridge's law by Knuckles · · Score: 1

    n/t

    --
    "When I first heard Daydream Nation it quite frankly scared the living shit out of me." -- Matthew Stearns
  2. Probable trajectory by paiute · · Score: 3, Funny

    NASA: There is an ELE rock inbound.
    White House/Congress: What's it going to cost?
    NASA: 100 trillion.
    WH/C: Fake News!

    BOOM!

    --
    If Slashdot were chemistry it would look like this:Cadaverine
    1. Re:Probable trajectory by Tablizer · · Score: 4, Funny

      Bruce Willis charges too much

    2. Re:Probable trajectory by PolygamousRanchKid+ · · Score: 5, Funny

      Bruce Willis charges too much

      Nah . . . we'll get Bezos or Musk to do it.

      Bezos would probably do it for free . . . because if the Earth was destroyed . . . nobody would subscribe to Amazon Prime any more.

      --
      Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
    3. Re:Probable trajectory by rmdingler · · Score: 1
      "Don't worry. Harry will do it. I know it. He doesn't know how to fail"... not sure Jeff qualifies, and Elon is on even shakier ground.

      If not for the magic of movies, we might be relegated to reality-based expectations of human behaviorial outcomes.

      --
      Happiness in intelligent people is the rarest thing I know.

      Ernest Hemingway

    4. Re:Probable trajectory by grep+-v+'.*'+* · · Score: 1

      Bezos would probably do it for free . . . because if the Earth was destroyed . . . nobody would subscribe to Amazon Prime any more.

      Don't worry -- Beos will surely save us. Besides, it'll be a business expense. Hell -- it'll probably end up as a made-for-Amazon movie as well.

      --
      If the universe is someone's simulation -- does that mean the stars are just stuck pixels?
    5. Re:Probable trajectory by Gavagai80 · · Score: 1

      Bezos would tell everyone he's going to do it, then spend 20 years failing to get a rocket into orbit. (Blue Origin was founded 18 years ago and it's safe to say they won't be reaching orbit in the next two years.)

      --
      This space intentionally left blank
  3. Re:No. It can do "something" but ultimately no. by CrimsonAvenger · · Score: 3, Insightful

    We aren't tracking what will kill us and even if we spotted it there's nothing we can do today.

    Probably true. On the other hand, working toward a solution is probably better than saying "well, we can't stop one now, so no point in looking." It's not like a solution will be easier to come by if we wait till the last possible minute to start developing one....

    --

    "I do not agree with what you say, but I will defend to the death your right to say it"
  4. If an asteroid has our name on it ... by Qbertino · · Score: 5, Insightful

    ... we're likely doomed. Plain and simple. We won the big lottery and we've had realive "asteroid peace" for a few million years now which had us evolve into quite smart apes but if some solid rock with a diameter of 1000+ meters comes at earth with 50000 kmh it's gonna hurt.

    Given, if we'd prepare for this sort of event we'd quickly be in a position to prevent it. But since we - right now - can't even get it down to stop dumping crap into the oceans and poisining the atmossphere, I wouldn't bet on that happening anytime soon. As long as idiots are still caught up in little more than extended tribal wars humanity won't move to that position. I sure hope we survive long enough to make that happen, but some sceptisizm and paranoia is due IMHO.

    If humanity does move on to becoming smart, we could also finally make a concerted effort to become a space faring civilisation. Maybe not beyond our solar system, but space faring none-the-less.

    --
    We suffer more in our imagination than in reality. - Seneca
    1. Re:If an asteroid has our name on it ... by terrycarlino · · Score: 1

      We might have the technology to put people on the moon for extended periods.

      We absolutely do not have the ability to get to Mars. As related above we do not have the capability at this time to deal with the radiation outside the Earth's magnetic field. Until that problem is solved no one is surviving interplanetary flight and all our efforts will be in low Earth orbit.

  5. No ... by CaptainDork · · Score: 1

    ... that would take science and money.

    Sorry.

    --
    It little behooves the best of us to comment on the rest of us.
    1. Re:No ... by PolygamousRanchKid+ · · Score: 3, Insightful

      ... that would take science and money.

      Congress Critters would waste precious time arguing about which states get the contracts to build the "Asteroiderator Killer".

      . . . and then we'd end up with 50 incompatible components built in 50 different states.

      "Thanks for all the fish!"

      --
      Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
  6. Space Force CAN by victorsosa · · Score: 1

    Nasa can't protect the USA from it; but the Space Force CAN ;)

    1. Re:Space Force CAN by Anonymous Coward · · Score: 1

      I'd have more faith in a new military branch with a zillion-dollar budget that it needs to figure out how to spend to make progress in space than NASA, which seemingly only exist anymore to get its budget cut (and to virtue signal about its newfound commitment to diversity).

      Whatever you think about all the useless billion-dollar fighter planes we piss away money on, you can't deny they're fucking cool as hell. The only reason we ever got to the moon was to win a cold war pissing contest with Russia; give the overfunded American military a plausible excuse to develop interplanetary space travel and we'll be running war games in the jovian system inside of 20 years.

    2. Re:Space Force CAN by terrycarlino · · Score: 1

      NASA--The only organization in existence which can make something like space flight boring.

  7. From the lad with Supesonic Dinos by See+Attached · · Score: 2

    We should be concerned about the size of the asteroid as the energy contained therein is proportional to the mass, but its proportional to the SQUARE of the speed... so we should be concerned with the size, but fascinated by the speed of the inbound. First,. it cuts down on our reaction time, second, speed is what brings the energy. Did like NM's treatise on Supersonic Lizard tails though: https://www.livescience.com/52... - I think I'd be twice as eccentric with half the cash!!!

    --
    Time for a new Political party in the US (or two!) One is off the rails Other cant pony up a leader.
    1. Re:From the lad with Supesonic Dinos by avandesande · · Score: 2

      A large slow asteroid is going to get more energy to the ground than a smaller faster one.

      --
      love is just extroverted narcissism
    2. Re:From the lad with Supesonic Dinos by Zocalo · · Score: 1

      Knowing the size, while a useful data point to have, doesn't really tell us all that much about the damage an asteroid is going to cause should it happen hit us, and actually seems like it would be a pretty poor metric of grading the probable damage in the event of an impact. What you also *need* to know for a probable impact damage assessment is the angle of impact (how much of the mass will be lost on entry, or will it just bounce off the atmosphere), composition (how much will burn up/probability of breakup on entry), mass (how much material might reach the surface), and velocity (energy to be expended on impact). Size does play a part though since the bigger the object is the bigger the atmospheric pressure wave it's going to create on entry, which can cause far more extensive and wide-ranging devastation than the crater formed by the impact, e.g. the Tunguska event, or some of the larger man-made blasts.

      --
      UNIX? They're not even circumcised! Savages!
    3. Re:From the lad with Supesonic Dinos by angel'o'sphere · · Score: 1

      If an asteroid is big enough to worry about hitting us, all those considerations are probably moot.

      --
      Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
    4. Re:From the lad with Supesonic Dinos by avandesande · · Score: 1

      Ever hear of ballistic coefficient? Yeah its a thing... plus the higher velocity meteor is more likely to explode in the atmosphere. Obviously you have been schooled stupid....

      --
      love is just extroverted narcissism
    5. Re:From the lad with Supesonic Dinos by Waffle+Iron · · Score: 2

      Any incoming projectile with enough energy to cause global devastation is more than likely large enough to make it through the atmosphere mostly unscathed. That's because it's highly unlikely that an incoming solid object will have a velocity above that of high-speed comets relative to the earth, around 70 km/s.

      If you could find some natural process that accelerates macroscopic objects to much higher speeds than that, then maybe your argument would have some relevance.

      The problem today is: NASA probably isn't detecting many new objects falling towards the sun even at 70 km/s in time to do anything about it. And as the GP post pointed out, these can be much smaller than an ordinary 20 km/s asteroid for the same amount of damage.

    6. Re:From the lad with Supesonic Dinos by angel'o'sphere · · Score: 1

      If an asteroid/meteor explodes depends on many things.
      I gave you the energy formula. Now google yourself.
      Whether a meteorite hits the ground depends mostly on its size ...
      Here e.g. is an interesting read, not sure that you comprehend it, though :P https://physics.stackexchange....

      --
      Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
  8. So, where to place your trust? by dwywit · · Score: 2

    NASA, an organisation with decades of experience with space-related matters, and decades of data from manned and unmanned missions, some fuckups but mostly glorious successes, or the ex-CTO of a company with a reputation for, well, a reputation like Microsoft's?

    Microsoft have been known to produce some good products, but they should *never* be first port of call when seeking technical solutions, or considering software.

    He probably wants counter-asteroid systems to all be running some version of Windows.

    --
    They sentenced me to twenty years of boredom
    1. Re:So, where to place your trust? by drinkypoo · · Score: 1

      "Microsoft have been known to produce some good products, "

      They've been known to buy some good products, stick their name on them, and then ruin them after a few years. They even managed to run windows 7 for the average user by turning Windows update into a malware delivery platform.

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
  9. Ten years by manu0601 · · Score: 1

    For a hypothetical attempt to send a spacecraft to divert an seriously dangerous incoming asteroid, we'll need a ten year heads-up

    I am certain it would take less than a few weeks to decide a nuclear strike against an asteroid.

    1. Re:Ten years by HiThere · · Score: 1

      You better know the composition and structural strength if you're going to decide that a nuclear blast would do more good than harm.

      If it were largely methane type stuff, then a nuclear blast off to one side would likely be better than direct impact. If it's iron, you'd better think of another approach.

      P.S.: Breaking it into fragments doesn't reduce the impact energy. It may cause it to spread, but it won't reduce it. (Of course, some of the fragments may have their orbit altered enough to miss us this time around...)

      P.P.S.: Please consider that for a large impactor an ocean strike is much worse than a land strike. If it lands in the middle of a large city, most life will survive, even though the city doesn't. (Unless some idiot decides it's an attack by a foreign government.) The dinosaur killer was as bad as it was because it landed in the ocean near the shore. (I don't know if deep water would have been better or worse.)

      OTOH, the most likely impactors aren't extinction event initiators. Most of them are at most city city killers. Or only a tiny bit worse. For those we might be better off if they land in the ocean.

      An additional consideration is that we don't get to choose. But how bad any particular event is depends heavily on just where it hits. If the dinosaur killer had hit in the middle of a continent, we probably would all be dinosaurs. (Possibly intelligent ones, but still, dinosaurs.)

      --

      I think we've pushed this "anyone can grow up to be president" thing too far.
    2. Re:Ten years by HiThere · · Score: 1

      Yeah, and depending on the size that might be significant. With a really large one, though, impact energy is the problem unless you can REALLY spread things around, probably to the extent that most if it will miss us this time around.

      A prior respondent suggested that this might be done with multiple nuclear explosions, and "maybe". The problem is you only get one chance to change the velocities of the pieces, so the follow on has to count on vaporizing them. You're after heat rather than explosive force, and not just radiant heat, as that only affects the surface, and is gone too quickly to penetrate. I think that this could probably be done with a custom designed nuclear weapon, but I think it's not the designs we've been building.

      Now with a 15 year lead there are several approaches that have been suggested that might work, particularly as with that much lead time you only need to nudge the orbit a trifle. The closer it gets, the worse the problem. If you could get the bomb the 5 years before impact, then exploding it just off to one side would probably change the orbit in time, particularly if you didn't break it up. But it we only see it 5 years ahead of time, it's likely to take us that long to decide what to do. And breaking it up when it's close isn't going to help much unless you also spread it a lot. Most of those things are rubble piles, though, and they break up when the hit the air anyway, but that doesn't do much to their momentum. A significant shock would probably require burying the explosive well under the surface...which is something that we haven't even done to a minor extent on an asteroid. (I think that there was one attempt that ran into trouble when the drill had it's solar cells end up in the shade...but that was *REALLY* minor compared to burying a significant bomb.)

      --

      I think we've pushed this "anyone can grow up to be president" thing too far.
    3. Re:Ten years by manu0601 · · Score: 1

      You better know the composition and structural strength if you're going to decide that a nuclear blast would do more good than harm.

      I do not know if a nuclear blast is the right approach. I am just confident this is the one that will be chosen.

    4. Re:Ten years by terrycarlino · · Score: 1

      Breaking up an asteroid spreads out the energy over multiple incidents. If you make the fragments small enough they might all burn up in the atmosphere rather than making groundfall. Maybe turning an extinction level event into a bunch of city killers. That's a good trade.

    5. Re:Ten years by terrycarlino · · Score: 1

      That's why you have to send Bruce Willis and his boys to do the drilling.

      Of course the radiation will kill them after they get the job done. Still bet you'd find people who would do it, just for the cred.

  10. Just call the Space Cowboys by Registered+Coward+v2 · · Score: 1

    If Clint Eastwood, Tommy Lee Jones, Donald Sutherland and James Garner can't do it, no one can. Not even the Gangster of Love...

    --
    I'm a consultant - I convert gibberish into cash-flow.
  11. Re:No. It can do "something" but ultimately no. by HiThere · · Score: 1

    Currently the answer is "no" whether they detect it in advance or not. I suppose if they found that something was on a collision course in 5 years they *MIGHT* be able to do something, but given current knowledge the something they could do would be as likely to make things worse as better.

    If there were 15 years warning, and goals didn't change with each election, then something reasonable could probably be done.

    --

    I think we've pushed this "anyone can grow up to be president" thing too far.
  12. What do the Las Vegas oddsmakers think? by swell · · Score: 1

    If we use our understanding of the past as a predictor, we could estimate that such an extinction event might occur every 1,460 billion days (4 billion years). There has only been one such event thus far and many life forms survived, including many mammals. We may have to wait even longer for the next one. But hey, we have nothing else to worry about so have at it!

    --
    ...omphaloskepsis often...
  13. Re:No. It can do "something" but ultimately no. by murdocj · · Score: 1

    Actually the question is really really simple... do we focus on the immediate threats to our survival (nuclear war, climate change, etc)? Or do we worry about much lower probability threats?

  14. A simple, DO-ABLE response: Moon Base + Kinetic by TheRealHocusLocus · · Score: 1, Interesting

    It is nice to see that the Obama-era plan has been fleshed out and in the current plan the real rubber-hits-the-road moment is,

    3.4 Identify, assess the readiness of, estimate in the costs of, and propose development paths for key technologies required by NEO impact prevention concepts. This assessment should include the most mature in-space concepts --- kinetic impactors, nuclear devices, and gravity tractors for deflection, and nuclear devices for disruption -- as well as less mature NEO impact prevention methods. Technology assessments should consider contemporary work, including potential synergies with relevant private industry interests (e.g., asteroid mining). They should also consider NEO impact scenarios that may have received insufficient attention thus far (e.g., binary asteroids, high-speed comets). [Short term; NASA, NNSA, DoD]

    Asteroid interception is where the goofiest ideas emerge to monopolize discussion and take debate away from practical ideas that would give us a chance of survival in all cases. When you interrupt geeks talking about their favorite solution, something like deploying solar sails to nudge asteroids, to point out their scenario is for an extremely narrow case and it would be irresponsible to pursue such an idea to the exclusion of more practical ones... they get all butthurt.

    My own solution which I've broadcast to Trump and two NASA directors and others, is simple and direct. No nukes or exotic technology.

    1. kinetic impactor rockets loaded with payloads of simple Lunar dirt
    2. missile battery on Moon, manned, truly ready to launch at a moment's notice
    3. hundreds, even thousands -- that can swarm to ensure multiplicity and mass
    4. the result: best possible assurance of deflect/destroy for any existential threat

    Anything less, or more, is a half solution or placebo fantasy to appease fanboys of exotic and impractical technology.

    --
    <blink>down the rabbit hole</blink>
    1. Re:A simple, DO-ABLE response: Moon Base + Kinetic by TheRealHocusLocus · · Score: 1

      What a rude little reply. I assume you're talking about 'threats' to Earth from such missiles while the threat from asteroids is... God's will? I'll put more effort into mine than you did, just quote a relevant bit from my letter,

      It is time for a global showdown between two major personality types of our time: those who are prepared to act quickly and decisively to mitigate this existential risk, and those who will oppose on many fronts... and it will be a showdown, for the opposition will attempt to 'quantify' the existential threat to a level where it could be passed over for this and the next generation, as has already happened, or dismissed altogether. They will call this 'logic, statistics and science' though it is none of those.

      It is a mental disorder.
      Great oratory is called for, stern resolve also.

      People who think they have plenty of time find it easy to propose or oppose anything, and language is rich with rhetoric of delay. Deficits grow less than we had feared, progress is made on countless fronts, we are closer now than ever before, love is just around the corner. In our developed world there are as many people able to survive by talking about things as those doing things. To the modern civilized mind global cataclysm is safely ensconced in speculation, early history, sacred text and cinema. Liberal arts education focuses deeply on the 'tabloid disasters' of history, strictly human atrocities that we and our neighbors would never repeat. It's someone else's job to think about such things, even if no one does. Easy to assume we are in the middle-weave of some tapestry between a dim beginning and distant end.

      Expect opposition to the idea that erstwhile enemies, even bitter enemies, should all come together to assemble a collective weapons platform that could -- through some mishap or menace -- send kinetic weapons down to places on Earth. A humorous cosmic irony, the ultimate Prisoner's Dilemma, that a whole species would knowingly seal its doom with its failure to trust one another as individuals.

      There is NO way to debate this to any unified consensus in the end. Despite the greatest tenets of all world faiths... the human race is experiencing technical difficulties, please stand by. The language of distrust and paranoia has become far more subtle and intricate, more lucrative, more fun, than the language of trust and action.

      It is my conviction then, that there can be no round table with talking sticks and common vote. One of the remaining superpowers must step forward to announce that it is committed to resolving this 'existential threat' for all of humanity... to begin immediately without debate. It shall be conducted transparently with assurance that others who come to agree such action is necessary, may join the effort.

      That is where America comes in.
      Apollo, showing that we could land on the Moon, was the first step.
      Artemis, goddess of the hunt, is next. Let us hunt space rocks.

      --
      <blink>down the rabbit hole</blink>
  15. I Wonder If It Matters by mschwanke97402 · · Score: 1

    The way things are going these days perhaps the cosmos hitting the reset button on earth would be a good thing.

  16. Error bars? by presidenteloco · · Score: 2

    The real problem it seems to me is, how accurately can you predict the trajectory and the collision, 5 or 10 years out, or even a year out?

    Would we spend the trillion-ish dollars to attempt to counter something that has according to calculations, say, a 1 in 10,000 chance of striking Earth in 5 years. Or say a 1 in 1 million chance. I'm guessing that the error bars might be at least that big.

    Anyone know the facts on that math and measurement and extrapolation capabilities?

    --

    Where are we going and why are we in a handbasket?
    1. Re:Error bars? by presidenteloco · · Score: 1

      That was my point.

      Note that for the probability of impact to be 1 chance in 10,000, you have to be able to measure the relative position with an error less than about 100 Earth diameters.

      Your error in the angle of approach of the asteroid, added to your error in Earth orbital position extrapolation, has to come to less than that amount. Very unlikely (impossible probably) to be that accurate years back from the possible collision.

      So political decision making would fail to allocate sufficient funds and time for response.

      The other problem is, with error bars, you probably don't know which direction to push the asteroid to be reducing the probability of impact rather than increasing it.

      --

      Where are we going and why are we in a handbasket?
  17. What Myhrvold's really thinking by 93+Escort+Wagon · · Score: 1

    “I’ve got a patent on 87% of the likely ways NASA would try to stop an asteroid, and a dozen east Texas lawyers on hot standby. To hell with trolling individuals... the US government has the deepest pockets of all!”

    --
    #DeleteChrome
  18. Nathan Myhrvold is smarter than NASA? Lol.... by TiggertheMad · · Score: 1

    Well spoken.

    Moreover, I am going to place a heck of a lot more trust in the the nerds as NASA, over a ex-CTO, because...oh wait....they are ACTUAL fucking rocket scientists. I'm sure that Nathan is clever and all, but I don't see anything in his CV that suggests that he is anything more than an armchair quarterback with 'opinions'.

    --

    HA! I just wasted some of your bandwidth with a frivolous sig!
  19. Moon Base + Kinetic == terible solution? by TiggertheMad · · Score: 2

    1. kinetic impactor rockets loaded with payloads of simple Lunar dirt

    Lunar soil is mass, but without a hard external jacket, it is going to crumble on impact and not behave like a rigid body. You probably want a inelastic collision to occur, not an elastic collision. Most space ships are made of very light material to save cost / fuel / delta V, it will be VERY expensive to ship vast quantities of 'bullets' to the moon with dense enough bodies that will not fragment on impact. The faster they are going when they hit, the harder it will be to keep them from shattering.

    Moreover, the amount of energy that you can impart on an object will be limited to the amount of mass that you can accelerate. Why not just put a few nukes up on the moon? The cost will be a vast fraction of what your bullets will cost, and with boosted yield fission weapons, you can get truly ludicrous yields. 50 megatons? not enough? 100 megatons? Bigger? Not even a problem. The US and Soviet Union stopped testing 'big' weapons because they had figured out that it wasn't hard to make a bomb pretty much as big as you wanted, and there was no point beyond anything that leveled a whole city or destroyed an entire army group. You aren't going to get 100+ megatons of KE imparted on an incoming rock with chemical rockets anytime soon.

    In fact, the only reason you would even need more than one up there (and not the thousands your idea requires) is because you want a few backups in case one is a dud. A (hypothetical) 500 megaton weapon would be just about the best way to nudge a rock in space into a new trajectory with existing tech.

    There is also the additional benefit that it is a good way to decommission military weapons. So aside from the fact your idea probably just won't work, is incredibly expensive to build and maintain, and we already have vast amounts of nuclear weapons already built that are way more efficient in terms of energy deliverable, your idea isn't a bad one. I give you full points for a creative solution to the problem.

    --

    HA! I just wasted some of your bandwidth with a frivolous sig!
    1. Re: Moon Base + Kinetic == terible solution? by triffid_98 · · Score: 1

      Good news, that isn't the only way to make space ships. We've even stockpiled plenty of 'fuel'.

    2. Re: Moon Base + Kinetic == terible solution? by triffid_98 · · Score: 1

      God damn it...it ate my href link https://en.m.wikipedia.org/wik...

    3. Re:Moon Base + Kinetic == terible solution? by Kjella · · Score: 1

      So aside from the fact your idea probably just won't work, is incredibly expensive to build and maintain, and we already have vast amounts of nuclear weapons already built that are way more efficient in terms of energy deliverable, your idea isn't a bad one. I give you full points for a creative solution to the problem.

      I think he missed the fact that we don't have any process to create fuel on the moon so we have to ship it from Earth. TLI -> LLO: 0.82 km/s, LLO -> moon: 1.87 km/s and the same in reverse to launch and break orbit, if you plug 2.69 km/s into the rocket equation you get ~50% fuel. So you can send 4 kg fuel, land 2 kg of it and use that to launch 1 kg Lunar dirt. But it would make a lot more sense to just launch 4 kg Earth dirt.

      If Musk realizes the BFR with full refueling it's pretty much the perfect asteroid defense, it should fit 5x Tsar Bomba and have roughly a 500MT yield while having the delta-v to actually deliver it. Maybe even more with a modern design, that one was just a rush job of many smaller bomb designs going off at once. Of course the power of 500 * 10^9 kg TNT isn't much against a dino killer estimated at 10^15 kg. That's one kilo of TNT to 2000 kg of rock, but should be enough to give it a nudge.

      --
      Live today, because you never know what tomorrow brings
    4. Re:Moon Base + Kinetic == terible solution? by TiggertheMad · · Score: 1

      If Musk realizes the BFR with full refueling it's pretty much the perfect asteroid defense, it should fit 5x Tsar Bomba and have roughly a 500MT yield while having the delta-v to actually deliver it. Maybe even more with a modern design, that one was just a rush job of many smaller bomb designs going off at once. Of course the power of 500 * 10^9 kg TNT isn't much against a dino killer estimated at 10^15 kg. That's one kilo of TNT to 2000 kg of rock, but should be enough to give it a nudge.

      Exactly. You aren't really trying to fragment the rock (which could create a bigger problem), just give it a nudge. You might not even want to detonate in contact with the asteroid. The main idea is that multi stage thermonuclear weapons can be made really big without a lot more effort, and it is much more powerful, efficient, and cheaper than KE weapons.

      A Castle Bravo class nuclear weapon + Saturn V class heavy lift rocket is doable and it is tech we already have. All we really need to do is keep looking up to spot problems before they get too close. It might turn out that the cold war nuclear weapons race is what saves humanity from a messy end.

      --

      HA! I just wasted some of your bandwidth with a frivolous sig!
  20. Asteroid Deflector by ShoulderOfOrion · · Score: 1

    That's what we need. Just make sure it's controlled by musical notes and only one person on the planet is given the knowledge of how to operate it.

  21. Comment removed by account_deleted · · Score: 1

    Comment removed based on user account deletion

  22. Re:No. It can do "something" but ultimately no. by hackertourist · · Score: 1

    We went from 4423 known asteroids in 1970 to 685231 known asteroids in 2015. So 'tracking what will kill us' is well on its way to becoming a solved problem.

  23. spacex to the rescue by cheekyboy · · Score: 1

    oh im sure $10b, and a rush order, spacex could build 5 FalconHeavys, to send USAs finest 2MT nukes to it.

    If push comes to shove, anything can be done as fast.

    --
    Liberty freedom are no1, not dicks in suits.
  24. Re:No. It can do "something" but ultimately no. by cheekyboy · · Score: 1

    oh and volcanos are no worries at all. For 1000000s of years they are harmless, and never have destroyed any cities or civs, or islands, or caused mini winters, or tsunamis that went inland 30 km. They are pretty harmless really - we are living on a liquid metal planet with a tiny thin layer of crumbs.

    --
    Liberty freedom are no1, not dicks in suits.