[HN Gopher] NASA's Double Asteroid Redirection Test Is a Smashin...
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       NASA's Double Asteroid Redirection Test Is a Smashing Success
        
       Author : DocFeind
       Score  : 135 points
       Date   : 2023-01-14 19:53 UTC (3 hours ago)
        
 (HTM) web link (eos.org)
 (TXT) w3m dump (eos.org)
        
       | originalvichy wrote:
       | Glad to hear. As crazy as it sounds, I believe that the biggest
       | apology we can give to the planet's inhabitants is using our
       | creations to shield Earth from a potentially catastrophic
       | asteroid that could wipe out vast amounts of life.
       | 
       | Yes, this "repayment" to Earth's biosphere is dulled by the fact
       | that we created weapons decades ago that could wipe out more life
       | than a relatively small asteroid could, but developing and fine
       | tuning these redirection methods is the least we could do to
       | protect this planet's life.
        
         | JPKab wrote:
         | Less than a year ago I made this exact statement in a thread on
         | hn where a bunch of people were talking about how humans are
         | like a virus on the planet.
         | 
         | I pointed out that the only thing in the history of the earth
         | that can stop the inevitable coming mass extinction from the
         | occasional asteroid are the hairless fire apes that have
         | learned how to harness chemicals to create rockets.
         | 
         | The responses were essentially calling me crazy and saying it
         | was fantasy.
         | 
         | The repayment is simply not dulled at all. Virtually every
         | medium sized or larger species on the planet gets wiped out on
         | the occasional large asteroid hit. A percentage of them going
         | extinct is a small price to pay for the majority staying alive
         | when the asteroid doesn't hit because we redirected it. For the
         | first time in its history the earth now has hairless fire apes
         | to act as an immune system against asteroids.
        
         | r3trohack3r wrote:
         | Over 75% of life on earth is behind us (4.2bn years).
         | Humanity's on a track to save life on earth from the complete
         | extinction event coming in 400M to 800m years. Humans are the
         | first (and very likely only) golden ticket our planet has
         | printed to get life off of this rock. We are heading to the
         | stars, and we will bring life with us.
         | 
         | Humans are awesome.
        
           | hammock wrote:
           | > Over 75% of life on earth is behind us (4.2bn years)
           | 
           | What do you mean by this? Are you predicting that life on
           | earth can only last for another 1.4 billion years? What
           | extinction event is so certain in the next 400m-800m years?
        
             | r3trohack3r wrote:
             | Less than 1.4Bn. AFAIK the carbon cycle grinds to a halt in
             | 400M-800M years:
             | https://en.m.wikipedia.org/wiki/Timeline_of_the_far_future
        
             | galangalalgol wrote:
             | The increased output of the growing sun will (ironically)
             | sequester _all_ the co2 due to weathering processes of
             | certain rocks. Then there will be no plants. It won 't take
             | long after that.
        
               | twoodfin wrote:
               | There isn't _that_ much CO2 in the atmosphere. This is
               | obviously a WAG, but I'd suppose that the planet-scale
               | geoengineering required to maintain plant-friendly CO2
               | levels in that changed solar environment would be at
               | least as feasible as developing a sustainable, coherent
               | interstellar civilization.
        
           | Xorlev wrote:
           | I love this comment. We're a walking disaster and a literally
           | hot mess, but you're right that we're probably the best
           | chance at preserving life overall.
           | 
           | > We are heading to the stars, and we will bring life with
           | us.
           | 
           | Another way to think about it: we'll be Earth's best, most
           | successful, furthest-flung seeds.
        
           | galangalalgol wrote:
           | We are the final stage of a Von-Neumann probe. We are
           | supposed to be identifying potential habitable planets, or
           | what will be by the time our launched packages of biologics
           | arrives.
        
           | jakear wrote:
           | Life would continue on earth after an asteroid (see:
           | history). The impact would only wipe out the most fragile
           | species, such as humans.
           | 
           | The same holds for nuclear war: life would continue as it
           | always has, species with poor nuclear hardening would be
           | selected against.
           | 
           | The true extraterrestrialism absolutists ought to encourage
           | nuclear winter and asteroid impacts; the life that makes it
           | out the other end will be much better suited for space's low
           | light low nutrient high radiation environment.
           | 
           | (/s...?)
        
             | Waterluvian wrote:
             | Nuclear disasters seem like a pretty solid way to create
             | blooming nature preserves. Why don't we do more of those?
        
           | xXTyrannosXx wrote:
           | Really I think we should go a step beyond this. Being able to
           | go to some new planet is not guaranteed or that planet may
           | even be inhospitable to us.
           | 
           | What I think is more feasible and more benevolent than
           | preventing a mass extinction is we should slowly expand our
           | orbit so we can survive the brightening sun for at least a
           | while longer. Basically, all we need to do is increase our
           | planets speed over hundreds of millions of years. A certain
           | mass of asteroids with steerable self correcting orbits could
           | push small amounts of speed into our planet that would build
           | up over time.
           | 
           | Even if we don't make it, we at least give life more time to
           | do it's thing.
        
         | hanniabu wrote:
         | This has "it's our planet to ruin" vibes
        
         | Waterluvian wrote:
         | My perspective is that "protecting this planet's life" is just
         | more human narcissism (this isn't a jab at you, it's a very
         | common mindset).
         | 
         | Short of total sterilization, mass extinction events seem to be
         | really good at creating space for new forms of life to develop.
         | In a way, preventing them in the name of the non-human life
         | here is just picking the incumbent over whatever comes next.
         | How would we feel if aliens stopped the mass extinction events
         | that led to our existence? I'm not sure there's solid argument
         | for why one is more deserving of existence than the other.
         | 
         | I think why this slightly rubs me the wrong way is it feels
         | like an excuse to make us feel good. Non-human life seems by
         | and large indifferent to its long-term fate on this planet.
         | Let's not pretend we do anything significant for non-human life
         | that isn't to our direct benefit.
         | 
         | Just my perspective. Not trying to say "no, you're wrong!"
         | Just, "I disagree." I'm going to guess there's an entire named
         | branch of philosophy that explores this.
        
           | ASalazarMX wrote:
           | > How would we feel if aliens stopped the mass extinction
           | events that led to our existence?
           | 
           | I would wager than as soon as a technological civilization is
           | born, it's morally reprehensible to let it go extinct, since
           | it no longer is at the full whims of evolution. It's complex
           | issue, so many people would wage otherwise, and only a jury
           | might reach a conclusion. The case is moot when said
           | civilization can avert extinction by their own hand, though.
           | 
           | I don't know about two technological civilizations in
           | conflict, like sapiens and neanderthals. Would it be morally
           | acceptable to let them go at each other, even if the fittest
           | extinguishes the other?
        
             | Waterluvian wrote:
             | > I would wager than as soon as a technological
             | civilization is born, it's morally reprehensible to let it
             | go extinct, since it no longer is at the full whims of
             | evolution.
             | 
             | I see the logic here. But why, though? And technology is
             | everywhere in non-human nature. While I think our
             | technology and civilization is unlike anything else here,
             | it's still on the spectrum of nature's exercise of
             | community and technology. Are we _really_ that special?
             | 
             | I think this heads towards the whole "Prime Directive" line
             | of reasoning.
             | 
             | P.S. Eloi > Morlocks, of course. ;)
        
               | avgcorrection wrote:
               | > I see the logic here.
               | 
               | There's no logic there. Just a faith in "potential".
               | 
               | It is arguable one way or the other whether
               | civilizational humans have caused more happiness or more
               | suffering for Earth (all of us lifeforms combined). So
               | the only way to call such a thing "morally reprehensible"
               | is if you assume that Civilization will eventually evolve
               | into some awesome, fantastic, space-faring, all-needs-
               | met, stewards of the near solar system fantasticness.
        
           | TylerLives wrote:
           | Given how long it takes for complex life forms to develop,
           | and how other planets known to us don't seem to have any life
           | at all, I think it's reasonable to prefer the existing life
           | to the future potential life, even from a non-anthropocentric
           | perspective.
        
             | chki wrote:
             | But why? Why are algae better than rocks and ants better
             | than algae if you take humans out of the equation?
        
               | hgsgm wrote:
               | Complexity is interesting.
        
               | chki wrote:
               | Why is complexity interesting if there are no humans to
               | observe it?
        
               | PKop wrote:
               | Closer to us, and we are great.
        
             | Waterluvian wrote:
             | Countless species of life have come, changed, and went over
             | billions of years. But we arrive in the last few hundred
             | thousand years and declare, "stop the cycling!"
             | 
             | I completely see (and share) your reasoning. But I think
             | it's very anthropocentric.
        
               | XorNot wrote:
               | Well guess what when there's no humans left alive,
               | whether this is anything no longer matters because the
               | value system died with them.
        
               | Waterluvian wrote:
               | If life blooms on a wet rock but nobody's around to say,
               | "that's pretty," did it matter?
        
               | XorNot wrote:
               | No, because your entire sense of what's "beautiful" or
               | "right" has died along with you and the rest of the human
               | race.
        
           | closewith wrote:
           | Total sterilisation is a guaranteed outcome on a long enough
           | time line.
        
           | hackinthebochs wrote:
           | >I'm not sure there's solid argument for why one is more
           | deserving of existence than the other.
           | 
           | I think an existence bias is defensible. Take it as an axiom
           | that suffering is bad and flourishing is good. I think its
           | clear that the suffering of something that exists is worse
           | than the lack of flourishing of something that doesn't exist
           | but could. Value is something that conscious creatures do,
           | and so value depends on existence. The states of something
           | that can prefer its own states should be valued over the
           | states of something that can't. Existing fish matter more
           | than rocks and potential fish. So the organisms that exist,
           | at least the sentient ones, should take preference.
        
           | dctoedt wrote:
           | > _I'm not sure there's solid argument for why one is more
           | deserving of existence than the other._
           | 
           | Maybe we're helping to build a universe, and we can do more
           | in that regard than single-celled organisms, cockroaches,
           | etc.?
           | 
           | https://www.questioningchristian.org/2006/06/metanarratives_.
           | .. (self-cite)
        
             | Waterluvian wrote:
             | I love this line of thinking. It gets me excited about Sci-
             | fi. But I think we may already have the technology to seed
             | life elsewhere.
             | 
             | We won't do it though because it's unsatisfying to our
             | narcissism. Imagine trying to sell the world on a trillion
             | dollar project where we shoot loads of bio-goo out into the
             | cosmos in thousands of directions, knowing it'll take eons
             | to maybe have an effect that'll then take billions of years
             | to produce a result we will never appreciate.
             | 
             | I think if we do any sort of proliferation of life, it'll
             | be of us, by us, for us.
        
               | hgsgm wrote:
               | > Imagine trying to sell the world on a trillion dollar
               | project where we shoot loads of bio-goo out into the
               | cosmos in thousands of directions,
               | 
               | It's funny to imagine that this might be _not_ how life
               | on Earth started.
        
           | dymk wrote:
           | Humans are really good at causing mass extinctions - just
           | look at how we've literally decimated the planet's
           | biodiversity since the dawn of man!
           | 
           | That's a lot of new space for new lifeforms to specialize in.
        
             | Waterluvian wrote:
             | But to our narcissistic displeasure, the biosphere acts on
             | a very different time scale.
             | 
             | But points to us for a world record pace speedrun on the
             | downturn side of it. It'll eventually bloom again once
             | we're done here.
        
               | rapind wrote:
               | The biggest brain fart of humanity is our tendency
               | towards monoculture (for scale). Nature is very obviously
               | showing us how to sustain an ecosystem and yet in our
               | incredible hubris we're like "nah, we got this". We just
               | want to swim upstream for the hell of it.
        
               | Waterluvian wrote:
               | I think one of our greatest flaws (and possibly main
               | reason we are here today) is that we're so self-centered.
               | 
               | Why do we monoculture if it will kill us long-term?
               | Because it benefits us short-term. (And hey, maybe that
               | gives us runway to solve the long-term problem).
        
               | XorNot wrote:
               | Nature doesn't try and do anything. Nature is constantly
               | trying to murder everything around it. The most lethal
               | diseases to man are natural, and often common skin
               | bacteria which everyone carries.
               | 
               | There's a viral form of cancer which is wiping out the
               | Tasmanian Devil right now, just because.
               | 
               | Nature and evolution has no plan and no morality, it has
               | survivors and a balanced ecosystem is a cold war
               | stalemate.
        
           | polishdude20 wrote:
           | If the universe causes an asteroid to hit earth and make all
           | life extinct or let's new life flourish, us saving the earth
           | from said asteroid is also an outgrowth of the universe.
           | 
           | We are not separate from nature and protecting the earth is
           | only natural for a multicellular intelligent species like
           | ourselves.
        
             | the_af wrote:
             | I think the argument is not that mankind preventing a mass
             | extinction event is unnatural, but rather that mass
             | extinction events seem both natural and necessary for the
             | rise of new life forms, and as such are "neutral" rather
             | than bad events (except from the perspective of mankind,
             | which would be rendered extinct). So it can be argued that
             | you are not necessarily making a "favor" to Earth's
             | ecosystem.
        
             | Waterluvian wrote:
             | For sure! And if a meteor is heading our way, I'll be on
             | the top of that hill with my Louisville Slugger.
             | 
             | I just think we shouldn't pretend that we're being
             | altruistic.
        
           | hparadiz wrote:
           | > mass extinction events seem to be really good at creating
           | space for new forms of life to develop
           | 
           | To what end? Life on this planet has about a 1 billion year
           | run way left since the sun will start to expand and
           | eventually strip away Earth's atmosphere and finally swallow
           | the planet whole. It's taken 3.7 billion years to get to this
           | point and most of the "interesting" evolution has occurred in
           | only the last 500 million years. So it is true that the next
           | 500 million should be even more diverse.
           | 
           | However unless another intelligent life form develops the
           | point is moot. No matter how smart a dolphin, or raven, or
           | chimp, or octopus is... if it can't escape this rock then
           | it's not much different from a bacteria colony that dies out
           | when it's food source is exhausted.
           | 
           | Evolution is random. For all we know an even more intelligent
           | form of life will develop than us humans but on the other
           | hand it's possible that for the next billion years we are the
           | only fluke in the evolutionary timeline and nothing else will
           | develop.
           | 
           | Finally there's a third option that is within the grasp of
           | humanity which is to say we can branch off Earth's tree of
           | life and take it into space while leaving Earth to develop as
           | it will.
        
             | Waterluvian wrote:
             | A billion years seems to be a LOT of time for many mass
             | extinction events. I think your argument leans on
             | "interesting" a lot, which has its basis in our narcissism.
             | Again, it only feels important that the life be
             | "interesting" if we're here to care.
             | 
             | Just to restate: I'm not saying we don't act selfishly. I
             | sure would. Let's just not pretend we're being altruistic.
        
               | hparadiz wrote:
               | The vast majority of evolutionary complexity has evolved
               | in the past 500 million years. That's what I meant by
               | "interesting". Things like flowering plants. It has
               | absolutely nothing to do with our branch of the tree of
               | life. So I'm not sure where your accusation of narcissism
               | is coming from.
               | 
               | For all I know a flowering plant will develop a brain and
               | become sentient in the next 200 million years.
        
       | curtisblaine wrote:
       | Stab in the dark, but can't this be used as a weapon? Covertly
       | redirect an adequately small asteroid near to the capital city of
       | your enemy, act horrified at the unlucky "natural disaster" that
       | happened, maybe even send help in a gesture of distension...
        
       | sbaiddn wrote:
       | In highschool we used an air hockey table to come to the same
       | conclusion: the laws of Newton are valid.
        
         | cj wrote:
         | I would wager that Isaac Newton would have been hesitant to
         | claim that an asteroid's trajectory could be modified by
         | humans.
        
           | IshKebab wrote:
           | Probably not if he knew humans could launch rockets into
           | space.
        
       | ur-whale wrote:
       | Mmmh, differential equations for N-bodies system have notorious
       | tendencies towards chaos and/or easily getting out of chaotic
       | attraction basins.
       | 
       | For that reason, I'm not entirely sure that playing cosmic
       | bowling with stuff floating around in the solar system is such a
       | good idea ...
        
         | ohyoutravel wrote:
         | I suppose the calculus might change when it's between the earth
         | getting smashed and the potential unintended consequences of
         | cosmic bowling.
        
         | baq wrote:
         | 'bowling' is hardly a good analogy here, though. it's more like
         | pea shooting at huge rocks, though in this case it turned out
         | that the rock in question isn't held together particularly
         | well.
        
         | xvedejas wrote:
         | When the relevant timescales are short, and most of the bodies
         | are small (so, weakly interacting), this is not so big an issue
         | mathematically.
        
         | ghaff wrote:
         | That probably assumes that cosmic bowling doesn't happen all
         | the time and that we're disrupting some finely-tuned system
         | that has kept earth (mostly) safe for billions of years.
        
         | QuadmasterXLII wrote:
         | Goin on the hn-gell-man chart
        
         | ealexhudson wrote:
         | More like cosmic pool, and we have Dave Cinzano Bianco Lister.
        
           | JaimeThompson wrote:
           | _Lie Mode_ Who?
        
         | spenczar5 wrote:
         | Hi, I work on N-body orbit determination software for asteroid
         | detection and planetary defense (for example,
         | https://github.com/moeyensj/thor). Ask me anything.
         | 
         | You're right that orbit determination is unstable over long
         | runs, and very sensitive to initial conditions. But the good
         | news is that the solar system is big. Most trajectories do not
         | intersect with the earth's location. So perturbing an orbit
         | that we think has a small chance of hitting us tends to be
         | safe.
         | 
         | Also, of course, after deflection, any object is going to be
         | monitored really closely for a long time.
        
           | Hendrikto wrote:
           | Maybe a bit off topic, but:
           | 
           | * What language is that software written in?
           | 
           | * What was the hardest problem you had to solve, while
           | working on it?
        
           | pageandrew wrote:
           | Since DART crashed into Dimorphos, changing its orbit around
           | Didymos rather than its orbit around the sun, isn't there
           | almost no cause for concern because Didymos is still on the
           | same non-intersecting orbit around the sun? Is the concern
           | that Dimorphos's slightly different orbit could pull Didymos
           | slightly off course in its orbit around the sun, thereby
           | causing it to _potentially_ intersect with Earth at some
           | point in the future, where it wouldn't have prior to DART.
           | 
           | Can we quantify how much Dimorphos's new orbit has affected
           | Didymos's orbit? Is that calculable?
        
           | nighthawk454 wrote:
           | Hey, this is a bit tangential, but is Barnes-Hut still used
           | in modern n-body simulations? Some of the math has huge
           | crossover with machine learning and dimension reduction, but
           | it's rarely traced back to the source in literature. Thanks!
           | 
           | (I'll also check out the GitHub repo you linked but I haven't
           | read it fully yet)
        
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       (page generated 2023-01-14 23:00 UTC)