[HN Gopher] Asteroid Impact on Earth 2032 with Probability 1% an...
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Asteroid Impact on Earth 2032 with Probability 1% and 8Mt Energy
Author : 2-3-7-43-1807
Score : 485 points
Date : 2025-01-29 12:47 UTC (1 days ago)
(HTM) web link (cneos.jpl.nasa.gov)
(TXT) w3m dump (cneos.jpl.nasa.gov)
| 2-3-7-43-1807 wrote:
| Full link:
| https://cneos.jpl.nasa.gov/sentry/details.html#?des=2024%20Y...
| perihelions wrote:
| You can email hn@ to ask them to fix a link.
|
| The title bot likes to strip URL parameters.
| dang wrote:
| In this case it changed the link because
| https://cneos.jpl.nasa.gov/sentry/details.html was listed as
| the canonical URL on the page. We've reverted that now.
| dang wrote:
| Fixed now. Thanks!
| lambdadelirium wrote:
| What can be done to increase the asteroid impact probability?
| jdmoreira wrote:
| We can land on it, drill and plant nukes inside to shatter it
| chrsw wrote:
| That's not what they asked
| littlestymaar wrote:
| It would definitely increase impact probability though.
| chrsw wrote:
| Not necessarily. See my new comment above. In addition,
| depending on how far out you do it, gravity will allow it
| to reform. And if it never reforms because you blew it to
| dust headed out to interstellar space you wont get an
| impact either. It's not at all a simple problem.
| ta1243 wrote:
| That would create far more objects, many on the same rough
| direction, thus increasing the chance of an impact
| chrsw wrote:
| Only if you managed to leave the trajectory the same if
| it was already on a collision course or change the
| direction to a collision course. Do you think you can
| control that with a nuclear explosion? You probably don't
| know enough about to the system to make a high confidence
| prediction of the new outcome.
| echoangle wrote:
| Not really, blowing it up is going to create a lot of
| fragments with slightly different orbits, and some are
| going to have practically the same as the whole Asteroid
| had before. So the chance of anything at all hitting
| earth will increase, but the parts will be smaller. It
| would be like a bullet turning into buckshot during
| flight.
| chrsw wrote:
| If we were talking about a projectile fired at relatively
| close range on the surface of the Earth I would agree
| with you. But we are talking about a very small object
| very far away with already only a 1% chance of impact.
| Buckshotting the object with a random explosion is
| unlikely to change the dynamics of system to point where
| you say with high confidence the chance of impact is much
| higher. Some fragments might hit but it's very difficult
| to predict.
| echoangle wrote:
| As long as some part of the asteroid keeps the old
| trajectory, the chance can only increase because you're
| adding particles with slightly different trajectories.
| pxmpxm wrote:
| Can't tell why I'm hearing "I could stay awake just to hear
| you breathin" in my head when reading the above
| vasco wrote:
| Get a lot of people to jump at the same time to nudge us into
| the path.
| 2-3-7-43-1807 wrote:
| that's a beautiful idea. it will only work if we act together
| as one human race. this is the moment where we have to put
| political conflicts aside and commit collective suicide.
| skykooler wrote:
| This would move the Earth by less than the width of an atom:
| https://what-if.xkcd.com/8/
| devsda wrote:
| So, we all have to just skip for a while ?
|
| There's a Sci-Fi Plot in there somewhere:
|
| A hero tries to and succeeds in persuading govts to
| organize a planet scale skipping effort to get earth closer
| to a passing by rock and escape an impending disaster on
| earth.
| vardump wrote:
| GP didn't specify Earth.
| mherrmann wrote:
| God I love HN.
| Timwi wrote:
| We're gonna need a bigger rock.
| Malcolmlisk wrote:
| Monke, smash!!
| Trasmatta wrote:
| And can we speed up the timeline? 2032 is too far away.
| chrisshroba wrote:
| Can we also add mass to the asteroid?
| tungah wrote:
| And speed
| Qem wrote:
| Waiting. In general the probability increases as more data is
| gathered, and the error ellipse shrinks with the Earth still
| inside. Then is suddenly drops to zero in the overwhelming
| majority of cases, when the Earth finally gets out of this
| shrinking error ellipse.
| dguest wrote:
| The _precision_ (of the observed trajectory) increases. If
| the probability increased _in general_ we should recalibrate
| our probability estimates.
| halfmatthalfcat wrote:
| Been rooting for Asteroid/Meteor in the recent presidential
| elections.
| chrsw wrote:
| The best way I can think of is similar to what I heard from
| Jaron Lanier (he may not be the first person to explain this).
| Basically what you do is send something massive out there that
| will gravitationally tug it into a collision course with Earth.
| Obviously this will take quite a bit of time but if your
| calculations are correct it will pretty much guarantee impact.
| arto wrote:
| https://en.wikipedia.org/wiki/2024_YR4#2032_potential_impact
| jonstewart wrote:
| If Mt of asteroid impact roughly equates to a nuclear weapon,
| then this is pretty bad for a metropolitan area but not enough to
| put a big dent in humanity.
| chrsw wrote:
| I think it if it's far enough out you only need to change it's
| trajectory only very slightly to reduce to the probably of
| impact to something much less
| ta1243 wrote:
| There's a 3 in 4 chance an asteroid hitting the earth will hit
| water, and of the remaining change about 50/50 it hits a desert
| or ice sheet (Antarctica, Greenland).
| jonstewart wrote:
| Hitting an ice sheet might be worst case scenario for global
| impact.
| pfdietz wrote:
| The stripe where this object could hit is mostly at low
| latitude.
| wing-_-nuts wrote:
| Sorry could you expand / clarify this comment? What would
| make this more likely to hit near the tropics?
| adzm wrote:
| The risk corridor calculated here https://en.wikipedia.or
| g/wiki/File:2024_YR4_risk_corridor.pn...
| vixen99 wrote:
| Depending on the amount, if landing on solid earth, the effect
| of dust ejected into the atmosphere might be critically
| significant in terms of energy dynamics and solar energy
| production.
| perihelions wrote:
| This is not an increase over baseline risk (as its Palermo
| scale[0] indicates, being a negative number, -0.56).
|
| I think there's going to be a crisis of media going forwards,
| because with the very awesome new telescope[1] that's going
| online this year, the number of these detections is going to
| drastically go up. The number of _objects_ isn 't going up--
| they've always been there, we just didn't know--but I think the
| media coverage is not going to absorb that nuance very well.
|
| [0]
| https://en.wikipedia.org/wiki/Palermo_Technical_Impact_Hazar... (
| _" A rating of 0 means the hazard is equivalent to the background
| hazard (defined as the average risk posed by objects of the same
| size or larger over the years until the date of the potential
| impact)_")
|
| [1] https://www.technologyreview.com/2025/01/01/1108643/vera-
| c-r... ( _" With its capacity to detect faint objects, [Vera]
| Rubin is expected to increase the number of known asteroids and
| comets by a factor of 10 to 100"_)
| roenxi wrote:
| HOWEVER this is an excellent time to review
| https://en.wikipedia.org/wiki/List_of_impact_structures_on_E...
| in particular the S2 to S8 spherule beds found in South Africa
| (AKA "the big one(s)" or "we are less than dust in the eyes of
| the gods").
|
| The universe is a big place with some big rocks in it. There
| are also some !!fun!! simulations of things like the Vredefort
| impact on YouTube.
| jofer wrote:
| See also:
| https://en.wikipedia.org/wiki/Australasian_strewnfield
| (debris over 10% to 30% of the Earth's surface from an impact
| ~788,000 years ago). Smaller, for sure, but very recent and
| large enough for "nuclear winter" type scenarios.
| deadbabe wrote:
| Why crisis? People should simply not look up.
| lioeters wrote:
| On the other hand, if people are told constantly to look up,
| eventually they stop looking.
| ALittleLight wrote:
| Or maybe we just build a system that can reliably detect
| and deflect asteroids and resolve the concern.
| mjd wrote:
| Obviously we should build a system which can reliably
| detect and correct people looking up and resolve the
| concern.
| virtualritz wrote:
| > Why crisis? People should simply not look up.
|
| I don't understand why this apt pun on that movie is being
| downvoted.
|
| Would anyone of the downvoters of parent care to explain?
| adastra22 wrote:
| Puns are for Reddit, not HN.
| umanwizard wrote:
| A lot of people think off-topic puns and jokes are
| annoying, and HN has a much higher concentration of such
| people than most of the internet.
|
| That's part of why discussion on HN tends to be much
| higher-signal than Facebook or Reddit.
| cscheid wrote:
| (I worked tangentially on software for analyzing data that will
| come from the Vera Rubin telescope, and) yeah, while it was
| designed for spotting weird supernovae and such, the first half
| of its operation is expected to be dominated by the discovery
| of near earth objects.
| DennisP wrote:
| So you're calling it a "crisis" that people will be better
| informed of the risk they've always faced? Seems to me we
| should use that media coverage to build political support for a
| real asteroid defense system.
| perihelions wrote:
| If the media does not contextualize risks correctly, as it
| never does, it's absolutely a crisis--a crisis of a poorly-
| informed, panicked society lashing out and doing irrational
| things.
|
| It's not a costless error if a warped illusion of risk drives
| countries to, i.e., deploy nuclear-tipped space weapons for
| asteroid defense, which then precipitate a _genuine_ crisis.
| It 's not obvious that having more defenses is obviously
| safer than having less; some thoughtful people have argued
| the opposite:
|
| > _" In our view, development of this asteroid-deflection
| technology would be premature. Given twentieth-century
| history and present global politics, it is hard to imagine
| guarantees against eventual misuse of an asteroid deflection
| system commensurate with the dangers such a system poses.
| Those who argue that it would be prudent to prevent
| catastrophic impacts with annual probabilities of 10^-5 would
| surely recognize the prudence of preventing more probable
| catastrophes of comparable magnitude from misuse of
| potentially apocalyptic technology."_
|
| https://sci-hub.se/https://doi.org/10.1038/368501a0 ( _"
| Dangers of Asteroid Deflection"_ (1994), Carl Sagan & Steven
| Ostro)
| DennisP wrote:
| In this case, the context is "we face the same risk all the
| time, from asteroids we don't see." I'm not convinced
| that's reassuring.
|
| The Sagan paper concerns much larger asteroids, which are
| correspondingly more rare. For asteroids in the 8MT impact
| range, it doesn't make much military sense to launch deep
| space missions to divert them years in advance, rather than
| delivering nukes directly with ICBMs in minutes. Given any
| competent asteroid defense system, an asteroid diversion
| would be detected immediately and countered, and the
| perpetrators would face consequences.
|
| In fact, since we already have rockets that can reach
| asteroids, I'd say the possibility of malicious diversion
| makes a defense system _more_ important.
| perihelions wrote:
| - _" The Sagan paper concerns much larger asteroids,
| which are correspondingly more rare."_
|
| That's a fair distinction--the paper predates the modern
| telescope surveys that are discovering all the small
| ones.
|
| - _" rather than delivering nukes directly with ICBMs in
| minutes"_
|
| You'd still need multiple years for those nukes to have a
| useful effect. (The change in velocity is instant; the
| change in position is not). They wouldn't be ICBM's,
| either: we'd need a new type of deep-space delivery
| vehicle, far larger than a suborbital ICBM. That'd
| probably trigger a new type of nuclear arms race.
| DennisP wrote:
| Sorry, what I mean is: why would I use my rocket and nuke
| to divert an asteroid years in advance, when I can drop
| an 8MT nuke on you directly in 30 minutes with much more
| accurate targeting?
|
| One possible reason is plausible deniability, but that
| goes away if we have a good asteroid defense system with
| an emphasis on early detection.
| perihelions wrote:
| Ah, I understand now.
|
| For one thing, you could weaponize asteroids as a second-
| strike response, if there's an imbalance where one
| superpower has asteroid deflection and one does not. Even
| if it's delayed by months, the certainty that the
| asteroid will _eventually_ hit establishes a deterrent
| against attacking the asteroid-controlling country. If
| there 's defenses against ballistic missiles, this
| circumvents those.
|
| For another, the asteroid-deflecting nukes are dual-use
| as weapons themselves. A nuclear warhead in deep space
| defeats conventional ballistic missile defenses. If that
| warhead is turned towards Earth, that (first-strike)
| attack's not visible to the adversary until a few seconds
| before impact--unlike an ICBM launch, which has tens of
| minutes of warning, enough to launch (conventional)
| interceptor missiles.
| wing-_-nuts wrote:
| Eh, we already have steath aircraft that could slip in
| past air defenses and drop a nuke with next to no
| warning. We _probably_ have a stealthy hypersonic that
| can also do so. That doesn 't negate a nations second
| strike ability.
|
| Part of the reason the US, Russia and China have _vast_
| land based missile fields is to visibly show the enemy
| that they 're gonna have to wipe out huge swaths of land
| with hundreds of nukes (and THEN sink our boomers) to
| have a successful first strike.
| perihelions wrote:
| Right; but if the enemy thinks that's likely to happen,
| it'd only take them 15 minutes to nuke that one airbase
| that stores all the B-2's. Strategic bomber aircraft
| aren't very useful weapons for superpowers fighting each
| other (or else we'd have a lot more B-2's).
|
| Space-based weapons (which are banned by treaty) are more
| like submarine-basing, in that the enemy isn't
| necessarily sure where they are; but, in addition to
| that, they have potentially very short warning times
| before a strike. No one actually _wants_ that unstable
| dynamic, with the short /no-warning; which is why all the
| nuclear powers have (so far) agreed by treaty not to
| build any.
|
| edit: But if someone were to build a _civilian_ spaced-
| based asteroid defense, which involved sending nuclear
| weapons into space... that could get destabilizing fast.
| Whether or not Sagan can predict specifics, the big-
| picture idea of humans not trusting each other with
| apocalyptic weapons is not wrong. (Worth recalling the
| USSR genuinely mistook the _civilian_ US Space Shuttle
| for a nuclear weapons platform).
| quesera wrote:
| Forgive my naivete, but do we really have the precision
| measurements and kT payload calibration needed to alter
| an asteroid's trajectory and speed to the point that we
| can target specific (even very large) country landmasses
| as the Earth's rotation exposes them to the oncoming
| projectile?
| perihelions wrote:
| No, nothing about asteroid deflection is precise; the
| physics are messy and we know little about them.
| XorNot wrote:
| ...boomer submarines exist.
|
| Nuclear second strike has _always_ been from the
| submarines, which guarantee a response within minutes.
|
| Versus your proposal here of launching a highly visible
| rocket, to manipulate a highly visible object, with a
| flight time measured in days to weeks that's mostly
| ballistic.
|
| Frankly: this is strategic nonsense.
| perihelions wrote:
| It's nonsense today, but technical factors change over
| time. It's unsafe to try to predict too far ahead.
| XorNot wrote:
| The physics of tomorrow though will be the physics of
| today however: a many months flight time out to an
| orbital object to affect trajectory change is a response
| time so far away as to be meaningless: any opponent with
| an ICBM strike capability on Earth could happily blast
| away your entire civilization, and reasonably expect to
| use the same technology that enables that ICBM capability
| to blast away (or deflect) your asteroid.
|
| Put it another way: for considerably less expenditure of
| effort, you could just build a hydrogen-bomb large enough
| to obliterate Earth's biosphere completely[1]
|
| [1] https://en.wikipedia.org/wiki/Doomsday_device
| perihelions wrote:
| Consider that ICBM's might not work forever. If e.g. new
| types of anti-ballistic missile defenses were to become
| cheap and reliable, then ICBM/SLBM's could even become
| obsolete (say, within the century). If that happened,
| there'd be a slew of new arms races, which are
| unimaginable to us, being beyond our technology horizon.
|
| Physics isn't changing over time, but engineering is.
| DennisP wrote:
| I don't think a second strike from asteroids would work.
| You can't just arbitrarily redirect an asteroid towards
| Earth whenever you want. You need one that's already
| going to pass nearby. You might have to wait decades for
| it to hit, and during that time your enemy can send their
| own nuke and nudge it away.
|
| But if you _could_ do second strikes with asteroids, that
| would be a good thing. Second strike capability helps
| prevent nuclear war. Effective first strikes are what 's
| destabilizing.
|
| Which brings us to your second point. I agree that
| stationing nuclear warheads in space is a bad idea. But
| we don't have to do that. With years or decades of
| advance warning, we can just launch them from Earth.
| perihelions wrote:
| - _" Second strike capability helps prevent nuclear war.
| Effective first strikes are what's destabilizing."_
|
| I don't disagree!
|
| - _" You need one that's already going to pass nearby."_
|
| There's a very large number of these already, within a
| small delta-v of Earth. We don't know where they are yet
| (it was a show-stopping issue with NASA's Constellation
| (?) program, when they wanted to demonstrate capturing an
| asteroid, but couldn't find one), but that's going to
| rapidly change.
|
| - _" and during that time your enemy can send their own
| nuke and nudge it away"_
|
| That's pretty useful: that brings it to a point where the
| defender has to invest an amount of resources comparable
| to the attacker. That's a win for the economically
| stronger country. If the difference grows large enough,
| they can simply overwhelm them with numbers.
|
| That's even before opening the technological
| possibilities of stealth asteroids.
| wing-_-nuts wrote:
| >we'd need a new type of deep-space delivery vehicle, far
| larger than a suborbital ICBM.
|
| Like...starship?
|
| > That'd probably trigger a new type of nuclear arms
| race.
|
| Why on earth would there be an arms race on something
| designed to deliver nuclear payloads to deep space? The
| _only_ way I could see that happening is if we had
| nuclear armed deep space colonies? (See, the expanse)
| sharpshadow wrote:
| This. It's a crucial step for our civilisation to be able to
| protect earth from any incoming dangers be it asteroids or
| Umuamua type objects. There must be a global effort with all
| countries to build such a system.
| rob74 wrote:
| Good luck with that... currently we are failing to muster a
| global effort for tackling climate change, which is a much
| more pressing issue than an asteroid which may or may not
| hit us. I know
| https://en.wikipedia.org/wiki/Don%27t_Look_Up is satirical,
| but reality often outdoes satire, so I wouldn't be
| surprised if things would play out exactly like in that
| movie...
| timewizard wrote:
| There is open doubt as to whether climate change, as
| presented, is truly a near-term existential issue.
|
| There is no doubt that an asteroid hitting earth is.
| freen wrote:
| There is an open doubt whether a fully functional coffee
| machine is currently orbiting Venus, however one of these
| hypotheses is different than the other.
|
| Hint: expertise matters, evidence matters, and in a field
| where buildings/laws/fields of study get named after
| successful contrarians, a long streak of effectively
| unanimous consensus should not be undervalued.
| timewizard wrote:
| The coffee machine has no implications on my current life
| span. It may be true, but who would waste their time
| caring about this?
|
| Show me the /unanimous/ consensus that this is an
| immediate /existential/ issue. I don't believe such a
| thing exists. When attempting to understand the
| difference between those who care about an asteroid and
| climate change, which was the question, this is the
| critical point to concern yourself with.
| Tepix wrote:
| by doubting, you've already ruled it out, haven't you?
| 95%+ is as good as it gets probably.
|
| For starters, we know corals will be dead in the next few
| decades, home of 25% of all oceanic species.
|
| The mass extinction event is underway and we aren't doing
| enough to stop it.
| timewizard wrote:
| > by doubting, you've already ruled it out, haven't you?
|
| So you are attempting to create an environment where
| reasonable doubt is impossible. This behavior is actually
| part of the reason I have doubts.
|
| > we know corals will be dead in the next few decades
|
| Do we?
|
| > The mass extinction event is underway and we aren't
| doing enough to stop it.
|
| This is a clever dodge of the original question. Can you
| explain to me when our current inaction reaches a point
| where no response will ever be able to overcome the
| drivers of this mass extinction? Do you have an estimate
| you can share?
| namaria wrote:
| Gotta be the acme of pedantic behavior to say "there's no
| proof climate change will kill ALL of us".
| quesera wrote:
| Unanimous consensus is an impossible goal.
|
| Overwhelming agreement among experts is as gold as
| standards get.
|
| But FWIW, I don't think anyone believes that climate
| change is a quick duration species-existential event.
| Massive slow-roll geopolitical destabilization leading to
| societal collapse? That's definitely on the table.
| timewizard wrote:
| > Unanimous consensus is an impossible goal.
|
| I know this. I was responding to the OPs appeal to
| authority.
|
| > Overwhelming agreement among experts is as gold as
| standards get.
|
| What is this agreement? That it will eventually happen?
| That's not much of an agreement.
|
| > I don't think anyone believes that climate change is a
| quick duration species-existential event.
|
| Among those who "agree" is there a common timeframe that
| they estimate? Or do they all have varying opinions on
| this?
|
| > That's definitely on the table.
|
| We have nuclear weapons. In bunkers. Aimed at "targets."
| Everything is on the table. This isn't useful.
| quesera wrote:
| I don't believe you would have any trouble answering
| these questions for yourself, and I do not have any
| confidence that you are engaging earnestly.
| freen wrote:
| Hmmm... what level of agreement would constitute
| sufficient cause for massive change?
|
| Eventually happen? What percentage of the Great Barrier
| Reef is gone?
|
| How about this every single climate change skeptic I have
| offered this wager to has declined to take me up: if in
| the next calendar year, the average global temperature
| for a given month is below the average global temperature
| of that month in the year you were born I will pay you 10
| times the amount you are willing to wager. If the
| opposite is true, that the month this year is warmer than
| the same month in the year you were born you must pay me
| the amount you are willing to wager.
|
| Care to take that bet? Didn't think so.
| dash2 wrote:
| The good news is that the near-unanimous consensus among
| experts is that climate change is _not_ an existential
| issue. Almost no climate scientist thinks that climate
| change could wipe out the human race. (That 's compatible
| with it having very large effects on human welfare,
| substantial percentages of global GDP.)
| paulryanrogers wrote:
| Existential to our way of life. That humans will survive
| in caves, and maybe even a few million, is cold comfort.
| mturmon wrote:
| This pessimism has its place, but in this specific case,
| it is not accurate.
|
| Congress did decide that NEO's are an important problem,
| and eventually money was appropriated to address it, and
| a technical solution to the detection problem has been
| found. (https://en.wikipedia.org/wiki/NEO_Surveyor)
| justinclift wrote:
| > There must be a global effort with all countries to build
| such a system.
|
| That bit doesn't really seem _necessary_ though?
| mmooss wrote:
| > I think there's going to be a crisis of media going forwards
|
| I take that as meaning a crisis of traditional media. But most
| of our false-positive and false-negative crises are crises of
| social media. Look at climate change, vaccines, ethnic hatred,
| pizza gate, every crazy rumor ...
| speps wrote:
| Two terms I never heard in the table for the asteroid:
|
| Parlermo Scale
| https://en.wikipedia.org/wiki/Palermo_Technical_Impact_Hazar...
|
| Torino Scale https://en.wikipedia.org/wiki/Torino_scale
| teepo wrote:
| I used genAI to help me understand the Palermo scale number
| seeming low.
|
| The 2032 asteroid does warrant tracking, but the Palermo Scale
| remains below a critical level because:
|
| The impact probability (1.2%) is not high enough to trigger a
| stronger alarm. The background frequency of 8 Mt impacts is
| relatively high, making this event less statistically
| exceptional. The event is still 8 years away, so uncertainties in
| orbital prediction remain.
| littlestymaar wrote:
| I find it fascinating that some people may brag about not using
| their brain like that...
|
| Asking a LLM about topics you have no idea about it a great way
| to be misled by hallucinations, don't do that.
| davidmurdoch wrote:
| It's actually a great way to find concepts to verify and ask
| questions about. You will often find out about tangential
| topics you otherwise would not have.
|
| I find it fascinating that people brag about refusing to even
| try to learn to use new tools just because they don't know
| how to use them effectively.
| littlestymaar wrote:
| > I find it fascinating that people brag about refusing to
| even try to learn to use new tools just because they don't
| know how to use them effectively
|
| Interesting how you jump to conclusion based on nothing.
| Had you checked my profile (even though it's even more
| obvious from my Reddit one) you'd have seen that I'm
| actually pretty savvy when of comes to language models.
|
| But knowing your tools also implies knowing their limits.
| ceejayoz wrote:
| I asked a parrot about quantum physics and it told me I'm a
| pretty bird.
| pxmpxm wrote:
| Could be LLM generated spam post to promote LLM generated
| spam?
| yread wrote:
| > Uncertainty region (3 sigma): 1.65 million km
| redeux wrote:
| For reference the Tunguska event, which was projected to be a 5MT
| explosion on the low end, flattened about 2000 square kilometers
| when it airburst. If this hits the ocean it would no doubt cause
| some large tsunamis.
|
| https://en.m.wikipedia.org/wiki/Tunguska_event
| teepo wrote:
| This one could be like Tunguska, an air bust maybe around 10km
| high. Would that cause a large tsunami?
| simne wrote:
| It depends, on where exactly will hit. Similar to nuclear
| explosions, if one happen over sea or ocean near coast, it
| will cause extremely large wave, which will be similar to
| tsunami. If it will hit land, will be small earthquake.
|
| This is why nearly all nuclear explosions was over land or
| far from coast. Few experiments near some coast or island,
| created tsunami-like wave on those coast (island), which
| considerable widen polluted territory (ocean is usually
| considered as self-cleaning).
| thot_experiment wrote:
| Only very locally, the Japan tsunami was an order of magnitude
| more energy and aiui earthquake tsunamis happen particularly
| with certain kinds of seafloor displacement. It's not just
| about the amount of energy but how that energy is applied,
| impact energies dissipate quickly with distance.
| layer8 wrote:
| Working link:
| https://cneos.jpl.nasa.gov/sentry/details.html#?des=2024%20Y...
|
| 8.1 megatons of kinetic energy. According to the Torino rating,
| only risk of "localized destruction" (less than "regional
| devastation"):
| https://cneos.jpl.nasa.gov/sentry/torino_scale.html
| beastman82 wrote:
| *megatons of TNT. 1 MT of TNT = 4.14*10^15 joules
| kristjansson wrote:
| So you wouldn't want to be under it, but a good-sized hill
| would be enough cover?
| simne wrote:
| Yes, deep underground shelter planned for nuclear attack
| will be enough to survive, as damaging mechanisms, are
| mostly same - short but very powerful infrared flash and
| deadly shockwave (better to consider it as very fast
| pressure grow and then pressure drop).
|
| Just staying behind hill, will be not enough cover from
| shockwave, so people will suffer from fast pressure
| changes.
|
| But shockwave quickly weakened as square of distance, and
| hill will make it's path longer. So, something like 100m
| hill could be considered as moving border of deadly zone
| 100m closer to epicenter.
| ortusdux wrote:
| Comparable in energy to a B-53 nuclear bomb, minus the
| radiation.
|
| https://en.wikipedia.org/wiki/B53_nuclear_bomb
| layer8 wrote:
| So a 14 km blast radius it seems.
| RandomBacon wrote:
| Unless it lands in the ocean in which case tidal waves, and
| if on land, probably an earthquake/shockwave.
| ortusdux wrote:
| A comparable ocean impact would be the 2004 Indian Ocean
| earthquake, which was about 3x more energetic.
| Gare wrote:
| I'd assume quakes transform much more energy into tsunami
| waves than meteorite hit does.
| fghorow wrote:
| That is not correct.
|
| Earthquakes' energy doesn't all go to displacing water
| and hence generating tsunamis. An ocean impact is
| significantly more efficient at transferring energy into
| tsunamis.
|
| https://www.sciencedirect.com/science/article/abs/pii/B97
| 804...
| giantg2 wrote:
| Interesting, I would assume surface wave dissipation to
| counteract that compared to seabed origin.
| cyberax wrote:
| 2004 Indian Earthquake was 9.1-magnitude, so it was about
| 150 megatons of TNT.
| ortusdux wrote:
| The USGS estimated 1.1x10^17 Newton-Meters of energy,
| which converts over to ~26Mt TNT.
|
| https://web.archive.org/web/20100404013939/http://neic.us
| gs....
| devoutsalsa wrote:
| What I just learned from ChatGPT...
|
| Asteroids mostly contain the same naturally radioactive
| elements we find in Earth's rocks - mainly potassium,
| uranium, and thorium in very small amounts. When they hit
| Earth, they don't typically create radiation hazards.
| Scientists have checked out famous impact sites like Meteor
| Crater in Arizona and found normal radiation levels. While
| impacts can briefly create some radioactive isotopes through
| the collision process, it's really the impact's explosive
| force that does the real damage, not radiation.
| dang wrote:
| Link fixed now. Thanks!
| vivzkestrel wrote:
| imagine if you could channel that much kinetic energy into a
| propulsion system for interstellar travel
| Ajedi32 wrote:
| The ESA's estimate is a bit lower, at 0.1 MT:
| https://neo.ssa.esa.int/search-for-asteroids?tab=possimp&des...
|
| I'm guessing there's still a lot of uncertainty.
| astrobe_ wrote:
| Those numbers were a bit abstract to me, so to get an idea:
| Tungunska event (1908) is estimated between 3 and 5 [1], and
| the Chelyabinsk (2013) at 0.5 [2]
|
| [1] https://en.wikipedia.org/wiki/Tunguska_event [2]
| https://en.wikipedia.org/wiki/Chelyabinsk_meteor
| barbegal wrote:
| I guess the probability of impact won't reach the >50% level
| until a few months before impact due to variations in earth's
| orbit and by that point the ability to do anything about it is
| limited.
| pfdietz wrote:
| > due to variations in earth's orbit
|
| I don't see how this could possibly be correct. Earth's orbit
| is very precisely known.
| hermitcrab wrote:
| I think the uncertainties are down to not precisely knowing:
|
| -the size of the object
|
| -the orbit of the object
|
| -the velocity of the object
|
| -effect of outgassing and solar wind on the object (as
| mentioned in the top comment)
|
| Rather than uncertainties in the earth's orbit.
| hidelooktropic wrote:
| So is anyone working on increasing those odds?
| scrumper wrote:
| Come friendly bombs and fall on Slough
| DonHopkins wrote:
| They're already workshopping how to blame the impact on DEI.
| Gibbon1 wrote:
| Since it's now okay to discriminate based on race and sex
| companies can put in their jobs ads 'no white men or Irish
| need apply'
| skykooler wrote:
| Given the predicted time, could we calculate which hemisphere is
| most likely for it to impact?
| belter wrote:
| It is listing 6 possible impacts.
| adastra22 wrote:
| But not the location.
| shrx wrote:
| It has already been calculated:
| https://en.wikipedia.org/wiki/File:2024_YR4_risk_corridor.pn...
| jcims wrote:
| About 16x the energy of the Chelyabinsk meteor.
| 34679 wrote:
| It's 1.2% cumulative over 6 passes that begin in 2032.
| NooneAtAll3 wrote:
| 1.3e-2 on the first pass, e-6 range and smaller on the
| following ones
| pella wrote:
| 2032 Mayan prophecy + 2024 YR4 = prime fuel for internet-born
| doomsday cults.
|
| _" The final katun in the sequence that must happen before the
| new cycle of the katuns begins again is 13 Ahau. This starts in
| 2032 and ends in 2052. It is the time from 2032 to 2052, that
| great earth changes may take place.
|
| The translation from the codices about 13 Ahau that starts in
| 2032 is 'Famine, plagues of locusts, and loss of rulers. The
| judgment of God' Mr. Scofield goes on to elaborate on this katun.
|
| 'This is a time of total collapse where everything is lost. It is
| the time of the judgment of God. There will be epidemics and
| plagues and then famine. Governments will be lost to foreigners
| and wise men and prophets will be lost.'
|
| It is my perception that the great crisis that many fear in 2012
| may well start after 2032. An interesting note to this time
| period is that it did bring great revolution and change during
| the time period from 1776 to 1796."_
|
| https://www.tokenrock.com/mayan-astrology/2012-mayan-prophec...
| IAmGraydon wrote:
| Hilarious. That article was written in 2021. We call that
| moving the goalposts.
| lou1306 wrote:
| Less exceptionalist American: the Maya predicted the
| Declaration of Independence
| xbmcuser wrote:
| Mayans did not follow the Gregorian Calendar so our yearly
| dates don't match they already had their apocalypse in 1500s
|
| " This is a time of total collapse where everything is lost. It
| is the time of the judgment of God. There will be epidemics and
| plagues and then famine. Governments will be lost to foreigners
| and wise men and prophets will be lost.'"
| jackcviers3 wrote:
| With the size of the asteroid, is this one where we could use the
| gravity tractor[1] or the Yarovsky Effect[2] techniques for
| deflection, or is there not enough lead time?
|
| 1. https://en.wikipedia.org/wiki/Gravity_tractor 2.
| http://ui.adsabs.harvard.edu/abs/2021plde.confE.119A/abstrac...
| simne wrote:
| To change orbit of so large asteroid, need huge amount of
| energy.
|
| Unfortunately, humanity now have only small power ready, for
| such far things just about 50kW, it will need decades to
| transfer so large energy.
|
| Russians claimed to create nuclear reactor for space with
| somewhere near 200kW, but unfortunately, now these are just
| words, very far from real hardware.
| ddahlen wrote:
| I work on the Near Earth Object Surveyor space telescope (NEO
| Surveyor) writing simulation code which predicts which objects we
| will see. This one has drummed up a bit of interest due to its
| (relatively) high chance of impact. I actually spent quite a bit
| of time yesterday digging through archive images trying trying to
| see if it was spotted on some previous times it came by the Earth
| (no luck unfortunately). Since we saw it so briefly, our
| knowledge of its orbit is not that great, and running the clock
| back to 2016 for example ended up with a large chunk of sky where
| it could have been, and it is quite small. We will almost
| certainly see it again with NEO Surveyor years before its 2032
| close encounter. I have not run a simulation for it, but I would
| not be surprised if LSST (a large ground telescope survey which
| is currently coming online) to catch it around the same time NEO
| Surveyor does.
|
| Our knowledge of the diameter of this object is a bit fuzzy,
| because of surface reflectivity, small shiny things can appear as
| bright as dark large things. This is one of the motivations of
| making the NEO Surveyor an IR telescope, since IR we see black
| body emission off of the objects, which is mostly size dependent,
| and only weakly albedo dependent.
|
| There is an even tinier chance that if it misses the Earth in
| 2032, it could hit the moon. I haven't run the numbers precisely
| for that one, but it impacted a few times in some monte-carlo
| simulations.
|
| If anyone is interested in orbit dynamics, I have open sourced
| some of the engine we are using for observation predictions:
| https://github.com/Caltech-IPAC/kete
|
| It is relatively high precision, though JPL Horizons has more
| accurate gravitational models and is far better suited for impact
| studies. My code is primarily for predicting when objects will be
| seen in telescopes.
| formerphotoj wrote:
| Thank you. Why I read HN!
| SubiculumCode wrote:
| If in 2032 an impact did occur, how much time before that
| impact would be able to ascertain over 50% probability of
| impact? hypothetically.
|
| That is, does the certainty increase steadily or non-linearly
| over time? Does near certainty of an impact occur from
| measurements taken just minutes before the impact, or hours,
| days, years?
| ars wrote:
| We would see it years before, and we would know with
| certainty years before.
|
| If the object really looked like it might impact I'm sure
| someone would get time on a powerful telescope to lock in the
| orbit.
| umanwizard wrote:
| How far in advance would we know exactly _where_ on the
| Earth it will hit? If, say, New York is going to be
| destroyed, it makes a big difference if we know that a year
| in advance vs. a day.
| dylan604 wrote:
| Does it though? People don't leave hurricane zones.
| People don't heed tornado warnings. I just have very
| little faith in humanity, and fell like "Don't Look Up"
| would be not too far off.
|
| Also, if you evacuate New York a year in advance, who's
| to say that the prediction isn't just a skosh off so that
| New York is left untouched but the real impact location
| was hit unprepared?
| umanwizard wrote:
| A lot of people do evacuate hurricane zones, even when
| death and destruction are not absolutely guaranteed. If
| we knew with certainty that a particular place was going
| to be hit by an asteroid, and we had time to evacuate, I
| am confident most people would do so.
| dylan604 wrote:
| The accuracy issue is the thing. I'd venture a guess that
| our prediction of the path of a hurricane 7 days out is
| more accurate than predicting where an impact will be.
| maushu wrote:
| It's actually the opposite. Calculating an asteroid
| impact is much easier because it primarily involves basic
| Newtonian physics. In contrast, the climate is a chaotic
| system, making long-term predictions far more complex.
| dylan604 wrote:
| I don't know how it's opposite. There's some complex
| guesstimating on where an asteroid will hit. We roughly
| know its size. We roughly know its composition. We
| roughly know its speed. We can give a +/- range where the
| impact area will be. That's not any different than how
| hurricane spaghetti models do.
| mmooss wrote:
| What was the compliance rate in evacuating parts of LA
| for the recent fires?
| heavyset_go wrote:
| There's always a few holdovers, but my experience living
| in disaster prone areas is that people evacuate when
| evacuation orders are given. Literally nobody is going to
| come help you if you don't.
| nickserv wrote:
| Having lived through a bunch of hurricanes in south
| Florida I can very confidently say people absolutely
| evacuate when given the order to.
| ars wrote:
| Knowing _if_ it will hit is a lot easier than knowing
| where.
|
| Knowing where, will depend on the angle of impact - if
| came basically straight in (tangent to the surface) we
| can be pretty accurate, but the more shallow the angle
| the harder it will be.
|
| With a shallow angle, we'll probably be able to tell the
| latitude pretty well, but not the longitude.
| jampekka wrote:
| Nitpick: normal to the surface.
| ars wrote:
| Oops! Yes, I meant to say perpendicular (or normal).
| mongol wrote:
| It must be easy to determine which face of the earth it
| strikes though...?
| umanwizard wrote:
| The earth rotates on its axis, So knowing the exact point
| it hits would depend on the exact time it hits.
| Presumably that's why the other commenter said knowing
| latitude would be easier than knowing longitude.
| mmooss wrote:
| > how much time before that impact would be able to ascertain
| over 50% probability of impact? hypothetically.
|
| I understand it's hypothetical, but even a 10% chance of
| hitting a city, for example, would be a crisis.
| 542354234235 wrote:
| They didn't say anything about 50% being the minimum level
| for a crisis. There is no "but" because they are two
| different topics. One is "how far out could an impact be
| predicted at 50/50 probability" and the other is "at what
| probability of impact would it become a serious
| issue/crisis".
| slackerIII wrote:
| Great post, thank you!
|
| Where does the uncertainty (1%) come from? For example, is it
| more from our ability to precisely determine the orbit based on
| limited observations, or is it because orbits for objects like
| this just aren't predictable years out, or something else?
| renjimen wrote:
| Parent mentioned Monte Carlo simulations, which allow you to
| simulate across a range possible scenario parameters and see
| what % result in some outcome (like a collision with Earth or
| the moon).
| VierScar wrote:
| I'm sure there's a reason, but it seems like an unusual use
| of Monte Carlo - it's all deterministic and there is no
| opposing player making choices. Must have something to do
| with uncertainties in projected orbits or imperfect
| simulations maybe?
| heikkilevanto wrote:
| Uncertain observations, I'm sure
| zacharycohn wrote:
| Right - we only got a short glimpse of it, not enough to
| get a high confidence of its trajectory.
| Projectiboga wrote:
| The guesswork is uncertainity about the object's exact
| paraneters. Because of this they have to use informed
| estimates (scientiffic guesswork).
| basementcat wrote:
| The observations are not 100% certain. There are a
| variety of body states and configurations that might
| result in the same (few) pixels being lit up in the few
| measurements collected so far. As additional measurements
| are collected, some possibilities may be eliminated and
| the uncertainty of the trajectory can be reduced. This
| usually results in the impact probability converging
| toward 0%.
| davrosthedalek wrote:
| ...or 100%. But yeah, the MC comes in this way. You have
| a current most probable value for the position and some
| distribution around it, depending on the precision of the
| measurement device etc. That can be a high-dimensional
| space. You draw some (many) random points from this space
| and propagate them all deterministically. Taking into
| account how likely a certain random point was in the
| first place, you can then estimate the hit probability.
|
| MC is numerically approximating an integral. Here it
| replaces the high-dim integral over the start parameters.
| cozzyd wrote:
| It is very common to use Monte Carlo for deterministic
| problems. It's just an integral over complicated PDFs
| NL807 wrote:
| >it's all deterministic and there is no opposing player
| making choices
|
| It's not deterministic, it's chaotic. That is the nature
| of the N-body problem. We can only approximate
| trajectories in such a system using numerical methods,
| within a certain margin of error. In principle, the
| object is gravitationally interacting with everything
| else in the solar system. But for the most part, most
| interactions are negligible and could be ignored (eg,
| other small objects far away), except of the large
| bodies. But there are many unknowns (as stated before),
| where initial conditions will affect the outcome of the
| trajectory simulation, and errors will certainly amplify
| over time. I'm guessing Monte Carlo is used to "fuzz" the
| simulations with randomised initial conditions to account
| for the range of unknowns, and see what the outcome is
| under these different scenarios.
| jaggederest wrote:
| At the very least you can use monte carlo to provide
| examples from the expected distribution. It's hard to
| visualize a probability cloud.
| coderenegade wrote:
| Chaotic doesn't mean non-deterministic, it just means
| that small changes in initial conditions result in a
| large change in the trajectory. The system itself can be
| both chaotic and deterministic.
|
| It's also a reasonable question to ask, because the
| simulations _are_ deterministic. It 's just that because
| the system is also chaotic and there's noise in the
| measurement, that can result in a large spread of
| deterministic trajectory simulations.
| NL807 wrote:
| It's only deterministic in the sense of the mathematical
| constructs that models the system, like differential
| equations that drive the simulations at each finite time
| step. But the information or the state which the
| simulation is applied on is always chaotic. That is
| because delta at each time step is an approximation with
| some error. It's impossible to make the state in the
| system behave deterministically, because that requires
| time deltas to approach to zero (or infinite amount of
| infinitely small differential steps).
| coderenegade wrote:
| Energy drift doesn't make the system non-deterministic,
| it just means that the time evolution has some error. The
| error is still deterministic. If you simulate a
| deterministic but chaotic system like n-body orbitals
| with a non-symplectic integrator, you'll always get the
| same result for the same initial conditions. The drift
| created by the finite timestep will also be the same.
| moktonar wrote:
| It's the error with the ground truth that you can't
| predict. Otherwise you would just be able to cancel it
| out. You can only predict probability distributions..
| coderenegade wrote:
| If you're saying that it's the uncertainty in the initial
| measurement, then we're in agreement. If the initial
| measurement were perfect, the only source of error would
| be the finite timestep. N-body simulation itself is
| deterministic, and so the only source of randomness is
| our uncertainty about the object's true mass, size,
| shape, position, velocity, etc.
| thekoma wrote:
| The N-body _reality_ _might_ be deterministic. The N-body
| simulation using digital computers will technically still
| introduce errors because of the time steps even if you
| had perfect knowledge of initial conditions.
| coderenegade wrote:
| The errors are deterministic. Determinism has nothing to
| do with the existence of errors, it's about uncertainty.
| They're different things. A system that is deterministic
| will produce the same results every time given the same
| initial conditions. If there are numerical errors, they
| will be identical for each run. A non-deterministic
| system will give you different results every time given
| the same initial conditions, with some variance. You can
| still have numerical errors in such a system.
|
| Ironically, reality probably isn't deterministic. It
| definitely isn't at small scales (e.g. radioactive
| decay). If it's non-deterministic at a macro scale, the
| effect is small enough that we don't see it.
| hoseja wrote:
| We don't know the configutation it's in precisely. We
| don't know the initial conditions. Small unobservable
| differences will lead to large difference in outcome.
| That's the chaotic part.
| coderenegade wrote:
| I get that. I'm pointing out that these are separate
| factors. Chaotic does not imply non-deterministic, and
| vice versa. The only source of randomness here is the
| uncertainty in the observation of the object, because (as
| you point out) multiple combinations of parameters could
| produce the same observation, and each one will have a
| different trajectory. The randomness doesn't come from
| the chaotic nature of the system, it comes from noise in
| our measurements. It also doesn't (as other posts are
| claiming) come from energy drift in the simulation,
| because that's also deterministic.
| refulgentis wrote:
| Right:
|
| - "Since we saw it so briefly, our knowledge of its orbit
| is not that great"
|
| - "[for example, in 2016 the data shows] a large chunk of
| sky where it could have been, and [the object is quite
| small."
|
| - "Our knowledge of the diameter of this object is a bit
| fuzzy, because of surface reflectivity,"
| baq wrote:
| Looks like alpha zero stole the original meaning of Monte
| Carlo... it is not required to have players, or a game,
| to use the method:
| https://en.m.wikipedia.org/wiki/Monte_Carlo_method
| bananaflag wrote:
| It wasn't stolen, it was a well-established particular
| case well before alphago
|
| https://en.wikipedia.org/wiki/Monte_Carlo_tree_search
| baq wrote:
| I only meant the total mind share :) looks like folks
| have never heard of MC in other contexts than game bots.
| RossBencina wrote:
| I would assume that it is because we have imperfect
| knowledge of the state of the asteroid (i.e. mass and
| current position/velocity/...). This imperfect knowledge
| is characterised by a probability distribution. Similarly
| the state of all other objects in the solar system is
| only known up to some distribution. To propagate the
| information forward in time to impact requires a
| complicated function f(state of solar system; state of
| asteroid). If all of the data was known (and expressible
| numerically) with perfect accuracy, and f were computable
| with perfect accuracy then all would be good. But as
| noted, (state of solar system; state of asteroid) is a
| probability distribution, and there are very few
| distributions and very few types of maps f that are
| amenable to analytic transformation. For example if the
| state was a normal distribution with mean x and
| covariance P, and f were a linear transformation, then
| x,P mapped through f is also normally distributed with
| mean y and covariance P_y, you can get the mean of the
| transform as y=fx, and P_y = fPf' (where ' indicates
| transpose). Needless to say our knowledge of the state of
| the asteroid and the solar system is probably a rather
| complicated distribution, and the n-body problem is not a
| linear transformation. Monte-carlo simulation is often
| used to propagate probability distributions through non-
| linear transformations.
| andrepd wrote:
| It's "deterministic" the same way the weather is.
| sdenton4 wrote:
| There's going to be some degree of measurement error, which
| will likely be greater for objects which have not been
| observed many times. Multiple observations should allow both
| better estimation of the object attributes (average out the
| noise), and allow some judgement of the quality of
| predictions given what you think you know about it.
| SR2Z wrote:
| My guess is that small objects like this suffer greatly from
| the 3-body problem, and multiple trajectories are generated
| from various starting points inside our measured error bars
| for the current states of these objects. Small inaccuracies
| compound over the years.
| mmooss wrote:
| > My guess is that small objects like this suffer greatly
| from the 3-body problem
|
| What bodies? My _impression_ is that the only objects
| around Earth with enough gravity to significantly impact
| trajectories are the Earth and Moon. Will the other small
| objects have any significant gravitational impact on this
| body?
|
| I also understand that in cislunar space, the Earth-Moon
| dynamic does create a three-body problem and trajectories
| are fundamentally unpredictable, with some exceptions. I
| wonder how that affects objects such as this one if they
| pass through the Moon's gravitational well.
| SR2Z wrote:
| Clicking the link, I found this visualization of the
| approximate orbit:
|
| https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=20
| 24%...
|
| This orbit is around the sun (as asteroids tend to) and
| the apoapsis is closer to Jupiter's orbit than Mars.
| pclmulqdq wrote:
| Also, the gravity of asteroids or small planetary bodies
| like moons that it passes close to will have some small
| effects that can add up over a long time period.
| slashdev wrote:
| The Sun, Jupiter, Saturn are the main ones. Depends on
| the orbit as to how much influence they have.
| baq wrote:
| Gravity has unlimited range, the patched conics method
| you think of is a good approximation on short time spans,
| but breaks down surprisingly quickly. Keep in mind the
| Sun moves all the water in Earth's oceans all the time...
| tofof wrote:
| Even if you're just doing a 2-body problem around the
| moon you'll get wildly wrong orbits over a timespan of
| just months if you treat the moon as a point mass (the
| way that's relatively safe to do with Earth, in
| comparison). Lunar mascons are so strong you can't even
| rely on a plumbob to point straight down if you want just
| tenth-of-a-degree accuracy. These perturbations are so
| severe there are only effectively only four (instead of
| 90) stable inclinations for low lunar orbits.
|
| Literally every body in the solar system acts on every
| other body at all times. All asteroids in the asteroid
| belt are perturbed by Mars and Jupiter, right? Except if
| you recognize the need to include Mars in calculating
| their trajectories, you need immediately to at least also
| account for the 4 Gallilean moons, who sum to about the
| same mass as Mars, and now you have a 7-body problem. You
| won't get correct results on trajectories of Earth
| approaches if you discount the mass of our moon, nor if
| you discount the rest of the asteroid belt (4% of our
| moon's mass)... etc.
| Galatians4_16 wrote:
| n-body problem.
|
| The planets, sun and all planetoids orbit the barycenter of
| the solar system, which in our case happens to be inside
| the sun. They all affect each other, making more than 3
| bodies problematic.
| bagels wrote:
| Mesurement uncertainty when propagated over long periods of
| time leads to very large uncertainties, imperfect gravity
| models, space weather
| ddahlen wrote:
| It's a bit of both, observing has uncertainty in a lot of
| places, if you are on the ground you get atmospheric effects,
| imprecision of timing, imprecision of optics, etc etc. You
| are also observing an object where you dont know how far away
| it is. That distance has to be solved by basically doing a
| sort of triangulation, which requires either the observer or
| the object to move enough. So if you observe over a short
| time (hours for example), you can see it is moving, but it is
| hard to tell distance.
|
| Once you have an estimated orbit, if it has any interactions
| with planets (IE: flyby of Earth), small differences in
| positions during the close encounter make LARGE differences
| decades later. Add to this the effects of photons from the
| sun pushing on the smaller asteroids or dust, or out-gassing
| /dust from comets cause these objects to slightly drift from
| just the basic gravitational forces. Generally inner solar
| system asteroids (inside mars) are very chaotic over hundreds
| of years, though typically predictable less than a century.
|
| Note that I am not an expert on impact calculations, I just
| know a bit about and and can do back of the envelope ones.
| There are a number of ways to get to the ~1%, the orbit fits
| have uncertainties on them and those can be propagated
| forward in time. However there are all sorts of complexities
| with doing that, and often the easiest method is to sample
| the uncertainty region a few hundred thousand times (Monte-
| carlo), and propagate those and see what hits.
| coderenegade wrote:
| Very cool. How are samples drawn from the uncertainty
| region? MCMC or does it simplify down? I'm guessing that
| this would drive the final percentage values that you guys
| determine, since the orbital dynamics would be
| deterministic.
| ddahlen wrote:
| I can tell you how I do it, but again I am not an impact
| study person. It helps to understand a bit of the
| background of how we fit orbits in general:
|
| 1) someone with a telescope sees something moving
| (typically these days these are bigger surveys)
|
| 2) These observations are submitted to the Minor Plant
| Center (MPC), the clearinghouse of all asteroid/comet
| observations.
|
| 3) Several groups pull observations from the MPC to fit
| orbits, including JPL Horizons (MPC also fits orbits)
|
| 4) You now have a pile of observations which you have to
| figure out which observation links to other observations,
| which is a complex math problem on its own. Solve that.
|
| 5) JPL Horizons for example then fits the orbits to the
| observations, and since the observations may be 100 years
| of data of wildly varying quality, from hand written
| notes in the 1920s through to modern data, this is very
| difficult. They publish a covariance matrix with the
| associated fit (IE: basically a gaussian error fit for
| the parameters).
|
| 6) I grab that covariance matrix and sample from it using
| some pretty vanilla statistics to build orbits.
|
| 7) Propagate and see what happens.
|
| Here is an example of an observation from 1950:
| https://caltech-
| ipac.github.io/kete/tutorials/palomar.html The image was
| developed on a glass plate, this one was never even sent
| in to the MPC, the guy taking the observation just wrote
| down "Asteroid" on the cover slip for the image. It was
| not formally discovered until the 1980s. We now know its
| orbit very well, so this particular observation is not
| that interesting other than as a curiosity.
|
| Here is an example of an orbit fit by JPL Horizons: https
| ://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=c%2F2..
| .
|
| Note the "condition code" on the right, which is a score
| of how good their orbit fit matches the data, 0 means we
| know the orbit with high precision. This one is an 8,
| meaning we have a fit, but its not that great. Most
| likely because we only have 31 days of observations.
| timewizard wrote:
| > JPL Horizons
|
| A slight tangent.. but my favorite thing about Horizons is that
| they still maintain a telnet interface to their system. Once
| you learn to use it it's quite a bit of fun to play around with
| it.
| nonrandomstring wrote:
| That warms my heart on a winter night.
| dzdt wrote:
| I wonder if we have a chance to catch it still on radar this
| pass. I know Arecibo used to do that and is now sadly gone, but
| Goldstone also has capability. Anyone know more?
| thenthenthen wrote:
| FAST [0] in China maybe?
|
| [0] https://fast.bao.ac.cn/
| grues-dinner wrote:
| FAST also doesn't have transmitters, unlike Arecibo. So you
| cannot do radar observations of radio-reflective but not
| emitting objects with it in the same way.
| me-vs-cat wrote:
| > if it misses the Earth in 2032, it could hit the moon.
|
| Oh, that's not so ba--- Wait, isn't that what happens in
| Seveneves?
| fnordlord wrote:
| I think that was supposed to be some kind of small black hole
| passing through the solar system or something more exotic.
| Maybe I'm misremembering. Great book though and still haunts
| me sometimes when staring up at the night sky:)
| intrasight wrote:
| I had also interpreted it as a small solo black hole. Which
| it itself a scary concept.
| YeGoblynQueenne wrote:
| Especially if it was a member of a band before going
| solo.
| zwily wrote:
| He never actually said what it was. I think some people
| floated theories, but the book never reveals the answer.
| dreamcompiler wrote:
| An 8 MT impact on the Moon is what the Moon calls "Tuesday."
| It has dealt with far, far worse.
|
| The impact probably wouldn't even be visible with the naked
| eye unless it hits a part of the Moon not then illuminated by
| the Sun -- in which case one might see a brief flash of
| light.
| mikeyouse wrote:
| Because I was curious and had no idea about the relative
| size of meteors that hit the moon, the one that hit the
| moon in 2013 and was captured by Spanish astronomers was
| traveling at 65k KPH and weighed about 400kg. That had an
| impact energy of 15 tons of TNT
| (https://www.youtube.com/watch?v=perqv4qByaI&t=1s)
|
| Safe to say, an 8 _megaton_ impact from one that weighs
| 220,000,000kg would be a bit more substantial! Apparently
| that would be roughly the size of the Meteor Crater in
| Arizona (https://en.wikipedia.org/wiki/Meteor_Crater).
| dreamcompiler wrote:
| Yes. Similar to hundreds of other craters on the Moon.
| nayuki wrote:
| > traveling at 65k KPH
|
| You could say 65 MPH (megametres per hour) ;-). Or more
| formally: 65 Mm/h or 18 km/s.
| dredmorbius wrote:
| SE leaves the question of exactly _what_ impacted the Moon
| unspecified, referring to it as the "agent". Both
| narratively and in-story, the question of what the
| _ramifications_ of the event are is far more significant than
| its origin. It 's not possible to change the past, nor does
| an understanding (narratively or in-story) have any
| appreciable impact on what transpires as a consequence.
|
| As others have noted, an 8 MT impactor on the Moon would be a
| quite minor event. It would likely be visible to terrestrial
| observers (if on the near-side) and leave a visible crater.
| Might generate ejecta which itself could enter the Earth's
| atmosphere over time, though likely with little effect on the
| ground.
| focusedone wrote:
| it's the agent...
|
| Read that book over a year ago and it's still eating at me.
| SamBam wrote:
| This happens in the YA book _Life As We Knew It_. A really
| great book (for a YA audience). I still feel cold remembering
| it.
| tmountain wrote:
| What are the implications of a moon impact? Would it affect
| life on Earth?
| euroderf wrote:
| Would Earth see on-again, off-again random showers of rocks
| of various sizes ?
| looofooo0 wrote:
| Do you know people worrying about supervulcano erruptions?
| defrost wrote:
| https://www.usgs.gov/observatories/yvo
|
| https://en.wikipedia.org/wiki/Yellowstone_Volcano_Observator.
| ..
|
| How concerned? https://www.agiweb.org/geotimes/june05/feature
| _supervolcano.... not very.
| solstice wrote:
| Could we stick an rtg-powered tracking beacon on it during its
| next flyby so that we can better calculate its orbit?
| amluto wrote:
| I would expect that a handful of retroreflectors, along the
| lines of lunar laser ranging, would be much less expensive
| and work about as well if not better. A radio beacon can give
| direction, at least within the precision of whatever array is
| used to locate it, but it does not directly give distance.
| And, with a reflective system, you can get extremely precise
| radial velocity by measuring Doppler shift, and all the fancy
| equipment needed is right here on Earth where it's easy to
| maintain and upgrade. Doppler measurements of a remote beacon
| are dependent on the quality of the remote clock, which adds
| complexity and dependence on gravitational redshift at the
| beacon [0].
|
| [0] I haven't tried to calculate how much this would offset
| the apparent velocity, but it seems very likely to at least
| be detectable.
| AISnakeOil wrote:
| Very interesting. How can we get rich from this?
| grapesodaaaaa wrote:
| I'm not saying this is a good idea, but conspiracy/prepper
| YouTube channels seem to be thriving off ad revenue these
| days.
| lupusreal wrote:
| There's too many of those, you'll never stand out from the
| crowd. Instead, you could make a channel where you
| react/review to specifically asteroid impact related books
| and media. It could be very low effort, but topical enough
| to gain traction as people search and watch other asteroid
| videos.
| twism wrote:
| Don't Look Up Vibes
| graycat wrote:
| Is that probability of an impact 1% or 1 = 100%????
| qnleigh wrote:
| 1%
| NooneAtAll3 wrote:
| it says 1% in the title, what's there to misunderstand?
| graycat wrote:
| 1% is tiny, really small.
|
| In my experience, commonly orbits in the solar system are
| astoundingly accurate over centuries. This prediction is
| relatively soon, 2032.
|
| So, we have (A) a crude orbit and only 1% prediction of
| hitting Earth or (B) an accurate prediction of 100% = 1.
| Between these two, (A) seemed too small and (B) too large.
| So, I asked.
|
| This question seemed appropriate enough.
|
| Reading the paper, sure, they have a lot of predictions for
| several decades to come with all the probabilities close to
| 1% and far from 100%. The paper gives some details on the
| difficulty of getting a very accurate orbit for the object.
| So, apparently the 1% is what they have in mind and their
| title, accurate.
|
| So, if it hits, what might be the damage?
|
| And it it does hit, what would be the probability of it
| hitting a densely populated area instead of ocean, desert,
| mountains, ...? Net, with the 1%, the risk of major damage
| seems quite small.
|
| Hmm, what would the insurance industry think? Vegas?
| XorNot wrote:
| 1% is 1 in 100.
|
| If you detected 100 objects with a 1% chance to hit, you're
| actually very likely to be hit by more the 1. There's a lot
| of objects up there, fortunately the chances they hit us
| are a lot lower then that so far.
| Willingham wrote:
| The impact to society would be much greater on a sociological
| scale then on a physical scale, many nukes are more than 8Mt, the
| likelihood of it hitting a highly populated area is lower still.
| elric wrote:
| I don't think I understand your comment. The yield of nukes is
| of no consequence if they're not being used, so I don't think
| the comparison stands?
| Willingham wrote:
| My point is, we have used nukes, so we know exactly what the
| worst case scenario is, and that's about 20-50 million
| lives(hitting Tokyo or NYC). Equal to the number of deaths
| during the Spanish flu or half of world war 2. I think the
| comparison helps us understand what the risk truly is. I
| think the world would panic and likely loose more lives
| through chaos than the actual impact.
| bunabhucan wrote:
| 3.8m for NYC , 3.1m for Tokyo
|
| https://nuclearsecrecy.com/nukemap/?&kt=8000&lat=40.72422&l
| n...
|
| https://nuclearsecrecy.com/nukemap/?&kt=8000&lat=35.6889853
| &...
| elric wrote:
| Losing 20-50 million lives through "panic" seems like a
| crazy estimate. What are you basing this on?
| NunoSempere wrote:
| I have an article looking at similar probabilities here:
| <https://blog.sentinel-team.org/p/how-likely-are-various-
| prec...>; for asteroids we gave 0.02% per decade of killing >= 1M
| people.
|
| One thing to consider is that for a 55m asteroid like this one to
| do a lot of harm, it not only has to hit the earth, it has to hit
| it somewhere very populated. (only about 0.3% of the earth is
| very urban https://nunosempere.com/blog/2024/10/16/urban-share/)
| hermitcrab wrote:
| Or hit the sea, which covers ~70% of the earth?
| defrost wrote:
| That's an interesting one, from the comment above yours
| linked article The Tugunska event of 1908
| instead had 50-60m, but caused only three deaths because it
| was over a sparsely populated area; it still affected 2.1K
| km2 (or about two NYCs worth).
|
| which raises questions about what kind of wave such an impact
| could create and what are the odds of _that_ hitting a
| populated coastal town (or three) might be.
| cyanydeez wrote:
| Thatll be dpn jrs first term so expect a "dont look up" sequel
| billiam wrote:
| fingers crossed!
| joeevans1000 wrote:
| Will the guess of an outcome improve over time?
| hermitcrab wrote:
| It will converge to 0% or 100% with more observations. With 0%
| more likely.
| m3kw9 wrote:
| It would have been scary even 2 years ago but by that time AI
| would solve that, maybe even turn it into some sort of mining
| operation
| hermitcrab wrote:
| By 'solve' do you mean 'write a limerick about'?
| m3kw9 wrote:
| You don't think we will have AGI or even ASI by then to have
| significantly improved tech? I would be we will
| hermitcrab wrote:
| An AI that can save us from an asteroid hitting earth in
| 2032? I think that is highly unlikely.
| breaker-kind wrote:
| what the fuck are you fucking talking about
| neilv wrote:
| Maybe it will start climbing in probability, giving us a chance
| to reflect, and to improve our ways.
|
| Since, if we're already doing Nazi salutes at a US Presidential
| inauguration, less than 100 years after we'd learned that Nazis
| are pure evil, then I'd understand if some higher power was ready
| to hit the reset button. Maybe tardigrades would evolve better.
|
| (ProTip: Be sure to send a second asteroid, to Mars, ahead of the
| Nazi escape ship.)
| FredPret wrote:
| You just Godwin'ed the crap out of this thing. Congratulations,
| I guess.
|
| https://en.wikipedia.org/wiki/Godwin%27s_law#:~:text=Godwin'...
| neilv wrote:
| In a time when, apparently, it needs to be said that "Nazis
| are bad", that's the best way I can imagine to spend hard-
| earned HN Internet Points.
| thg123712 wrote:
| That salute stuff is just to distract people, maybe it was even
| carefully planned.
|
| I'd rather focus on Bitcoin, AI and Blockchain scams as well as
| nepotism. The official excuse for Ramaswamy's DOGE exit is that
| Musk has a tech approach to solving (?) the efficiency
| problems:
|
| https://www.newsweek.com/vivek-ramaswamy-asked-if-elon-musk-...
|
| Expect a lot of blockchain nonsense infiltrating the
| government, perhaps even a digital currency. _That_ must be
| avoided at all costs.
| mrguyorama wrote:
| Doing nazi shit as a distraction is, and let me be clear,
| _not less bad than just being a fucking nazi_
|
| I know they are looting the nation. I know they are trying to
| create their techno-fuedal crypto shithole empire where only
| Musk and Thiel get to choose who knows and does what.
|
| But they are STILL building internment camps and already have
| had planeloads of brown people flown to random countries.
|
| Another reminder that Nazis and Facists are utterly
| inefficient at anything because of their incompetence and
| stupidity. The price we paid to fly those brown people out of
| our country could have bought them all first class tickets on
| civilian planes in the fucking free market.
|
| Nazi Germany and Facist Italy were both staggeringly stupid,
| incompetent, inefficient, and run by people who spent every
| day insisting they knew better than anyone around them, and
| literally criminalized proving them wrong. "At least
| Mussolini made the trains run on time" was always false.
| Empirically, the trains didn't run very well.
| userbinator wrote:
| Alternatively, perfect timing for a "US saves the world"
| moment.
| idunnoman1222 wrote:
| Probability 1% percent with a 50% margin of error
| kaikai wrote:
| 8 megatons is like the Tunguska impact, so not planet-destroying.
| bagels wrote:
| It needs a pictogram to help understand how destructive 8Mt of
| energy is. Is this a cool light show? Worldwide extinction?
| coolspot wrote:
| Medium scale nuclear test. Largest was 50Mt
| jampekka wrote:
| https://nuclearsecrecy.com/nukemap/?&kt=8000&lat=40.72422&ln...
| indigodaddy wrote:
| If it is determined years ahead that it will hit, will there be a
| months to years ahead period where we will know the exact
| target/landing spot, eg so we can have evacuations of the
| impacted area and surrounding areas?
| dylan604 wrote:
| at those scales, the off by a degree type errors make a huge
| difference. if you're off by a small margin so that a direct
| impact to NYC is off to the east, then you still have tsunami
| issues coming to NYC. so that might not be a direct hit, it's
| still within blast radius.
|
| with the earth's surface being 70% water, that means a greater
| chance of a water impact. so there's hope there, except that
| damn tsunamis again. maybe we can convince the asteroids to hit
| the spacecraft cemetery
| energy123 wrote:
| The errors should be a function of time until impact. I'd
| like to know what that error variance vs time plot looks
| like.
| K0balt wrote:
| Any idea which hemisphere is going to be exposed to the (low)
| risk of impact?
| i_am_a_squirrel wrote:
| Is there a "sweet spot" for asteroids where they don't impact the
| earth, but come within like 20 meters of it?
|
| Like is it possible for an asteroid to give a city a "buzz cut"
| and then continue on into outer space?
| Vampiero wrote:
| realistically any scenario is possible if the asteroid is going
| fast enough
| pbmonster wrote:
| ...and dense enough and with enough shear strength and yield
| strength. Air blast disintegration is making a lot of
| scenarios impossible.
| dylan604 wrote:
| > but come within like 20 meters of it?
|
| _like_ is doing some heavy lifting here. We have had asteroids
| pass by at a distance closer than the moon. That 's pretty damn
| close in my book relative to the size of the cosmos. At that
| scale, that's pretty much a ringer in horse shoes.
|
| The buzzcut is a very strange question though. If the thing
| enters the atmosphere and does not burn up, it is hitting the
| ground.
| ahazred8ta wrote:
| You are slightly mistaken. There have been hit-and-run
| asteroids that entered the upper atmosphere and skipped
| through.
| https://en.wikipedia.org/wiki/1972_Great_Daylight_Fireball
| The Grand Teton Meteor / The Great Daylight Fireball of 1972
| came within 35 miles of the surface. A huge iron meteor might
| survive a low pass but this would be a very rare event.
|
| https://en.wikipedia.org/wiki/Category:Earth-
| grazing_firebal...
| potamic wrote:
| In 1972, someone happened to have a camera when this passed
| by and captured an absolutely gorgeous shot with the Tetons
| in the backdrop.
|
| https://www.gardenofmemory.net/the-great-daylight-
| fireball-o...
| ahazred8ta wrote:
| video: https://www.youtube.com/watch?v=4WlCfuPrszU --
| https://www.youtube.com/watch?v=G4nP9jcFBJQ
| Aachen wrote:
| 35 miles is hardly a 20 meters' "buzzcut". The odds of that
| happening are probably worse than winning the lottery
| seventeen years in row
| xenadu02 wrote:
| Anything that comes closer than the ISS (give or take) is going
| to interact with the atmosphere which is going to change the
| dynamics considerably. Generally something with the right orbit
| to pass 20m above the earth's surface is going to burn up in
| the atmosphere or hit the surface. The drag is going to kill
| its orbit fairly quickly.
|
| To have enough energy to come that close without doing so means
| it has enough energy that superheating the atmosphere or
| generating nuclear events through impacts with air molecules
| starts to become a problem (or both: first one then the other).
| This is the "baseball at the speed of light" type problem from
| XKCD.
| pbmonster wrote:
| If you come in at exactly the right angle (because you'll
| skip off the upper atmosphere if you come in too flat) and if
| you're fast enough, it's entirely possible to enter the
| atmosphere but fail to complete the aerobreaking maneuver,
| resulting in an exit from the atmosphere at above escape
| velocity.
|
| The stress of this maneuver is considerable, especially if
| you get as low as 20m above ground, so the object would need
| considerable shear strength and yield strength. Also high
| density and high thermal capacity. But not unrealistic, I
| think a tungsten ball (or better yet, a solid tungsten
| lifting body with aerodynamic steering authority) should make
| it through.
|
| You can even exit the atmosphere but not have escape
| velocity, effectively using the aerobreaking maneuver to
| assist in the gravity capture of your object. But you'd
| better circularize the orbit shortly after, otherwise your
| next pass through the atmosphere is going to be terminal.
|
| Relativistic baseball effects aren't very relevant yet, I'm
| talking about objects hitting the upper atmosphere with
| around 20-50 km/s. Enough to leave again, not enough to start
| a fusion reaction.
| csomar wrote:
| I am not that good in physics so someone should probably
| correct me but if an object comes at such a speed that it
| escapes earth gravity, it'll probably eject us from our solar
| path into the unknown.
| hermitcrab wrote:
| The mass of such an object is likely be miniscule compared to
| the mass of the earth. So even a very close approach isn't
| likely to make much difference to the earth's orbit.
|
| E.g. an asteroid 100m across with the same density as the
| earth is going to have ~0.0000000000001 the mass of the
| earth.
| csomar wrote:
| Mass is relative to speed. If the object has a very high
| speed, it can reach the mass of the earth or even higher.
| That's why my understanding is that if it can escape the
| gravity of the earth, it means its own gravitational field
| is as or more powerful.
| hermitcrab wrote:
| The mass of an object increases appreciably with velocity
| only at relativistic velocities. This is completely
| irrelevant at the speed an asteroid is likely to be
| travelling.
|
| If an asteroid travelling at relativistic velocity passed
| through the atmosphere, a change in the earth's orbit
| would be the least of our worries!
| echoangle wrote:
| That's only relevant at relativistic speed, an Asteroid
| isn't going to come in at 10% of the speed of light.
|
| An Asteroid is going at most about 70 km/s:
|
| https://astronomy.stackexchange.com/questions/20805/what-
| are...
|
| That's 0.02% of the speed of light (300 000 km/s).
| tim333 wrote:
| I don't think a 20m buzz cut and back to space is possible. To
| get back to space you need at least low earth orbit velocity
| which is about 16,000 mph and stuff going that speed low in the
| atmosphere gets very hot and would probably melt and break up.
| Maybe if it was a big one some would break off and some make it
| back.
| le-mark wrote:
| With the cheap kg to orbit heavy lift systems coming online,
| these near misses are becoming opportunities for vast riches if
| they can be captured and mined. Less massive making the orbit
| easier to change.
| dylan604 wrote:
| Why change the orbit? Just lift off way in advance, land on it,
| mine it, then when the orbit is close just lift off at closest
| approach
| le-mark wrote:
| The mined material (ie the entire asteroid depending on its
| composition) would still require delta v to a suitable orbit.
| dylan604 wrote:
| you have to have delta v regardless. enough for your mined
| material, or the entire mass of the asteroid. i seriously
| doubt we'd ever approach ability of completely mining the
| whole of the asteroid.
|
| however, if you removed enough mass from the asteroid,
| would you end up screwing yourself by now changing the
| orbit so that the next time it swings by it's more of a
| direct trajectory?
| cyberax wrote:
| Giant meteor for President! Finally!
| eddieh wrote:
| Basically the same odds of dying in a car crash over your
| lifetime. So unless you give up on driving or being a passenger
| of a car--this is a meaningless risk, and besides that, it is
| even less likely to hit land, let alone a populated area. The
| chance that this will impact _you_ is unbelievably low.
|
| This is so below the threshold of worry, I'm shocked by the
| points and comments.
|
| Schedule a colonoscopy, quit drinking, resign from your high
| stress job, drive less, get your moles checked; all better
| mitigation for prolonging you life than worrying about this.
| insane_dreamer wrote:
| Woah. A 1% probability is a lot higher than I expected and am
| comfortable with (not that I can do anything about it)
| jampekka wrote:
| Urban areas are only about 0.5% of earth surface, so rough
| approximation of a catastrophic hit chance is around 0.005%.
| The chance of you specifically being affected by this asteroid
| is vanishingly small.
|
| You should personally be more worried about crossing a road or
| plugging in an electric appliance or being hit by a lightning.
| For others there's a lot more devastation going on globally
| that you could even do something about.
| thebruce87m wrote:
| Depends if it causes tsunamis
| jampekka wrote:
| An asteroid that size doesn't cause a very far reaching
| tsunami.
| insane_dreamer wrote:
| Not really worried that it'll impact me directly, but rather
| the damage that it could cause if an urban area anywhere in
| the world.
| maxglute wrote:
| That risk corridor covers the many of the highest populated areas
| of Africa... and ends in India.
| hermitcrab wrote:
| This article (despite the click-bait headline) has some
| interesting background on asteroid risk in general and 2024 YR4
| in particular:
|
| https://starwalk.space/en/news/should-you-worry-about-an-ast...
| anshumankmr wrote:
| 8Mt would be on par with a major nuke, right? Or will it become
| more energetic? or did I get it wrong?
| vixen99 wrote:
| In terms of the general topic of asteroid impact and risk, here
| is a highly informative reference.
|
| https://cneos.jpl.nasa.gov/pd/cs/pdc25/ImpactRiskIntro-ATAP-...
| DrNosferatu wrote:
| Wouldn't blowing it up into smaller pieces reduce the overall
| risk by having more of the bolide's original mass consumed in the
| atmosphere?
| elif wrote:
| Completely out of my domain and seat of pants rationing here, but
| although the impact probability is 1%, aren't we far far more
| certain about the /time/ at which it would strike earth? Could
| humanity collectively just migrate to the side of the world that
| will be shielded for a day?
| openrisk wrote:
| Knowing humanity and its ability for planetary level
| solidarity, its more likely that the most powerful nations
| would simply _displace_ the weaker ones. "No offence bro, but
| _we_ are the salt of the Earth, so get out of here and good
| luck ".
|
| What about empty places? Luckily for Greenland, the
| calculations predict that the flux of impacts to the poles for
| Earth is 22% greater than the flux at the equator [1]. So
| nobody (in their right mind) would want to annex it as an
| asteroid survival backup site.
|
| [1] https://iopscience.iop.org/article/10.3847/PSJ/abefda/pdf
| crazygringo wrote:
| The bad news is no, we have nothing even remotely close to the
| infrastructure necessary to move half the world's population.
| We don't have the transport, being limited to planes and boats
| mostly.
|
| The good news is that, worst-case scenario, this is going to
| wipe out a city. And cities and their surrounding areas can
| absolutely be evacuated. We definitely have the cars and buses
| necessary for that.
| elif wrote:
| My mistake, my understanding was that an event of this
| magnitude could cause seismic/volcanic activity. Didn't
| realize it was so localized
| elif wrote:
| But in any case, we certainly have the logistics to move
| populations given the timeline. Not everyone has to evacuate
| and return within a 3 day window.
|
| Even without incentives, in all likelihood, those who can
| will evacuate early for peace of mind, and as the prediction
| becomes more certain on its approach through measurement,
| individuals will I'm sure even start to return /before/ the
| pass. You know everyone has their own set of 9s to chase
| crazygringo wrote:
| No, we don't.
|
| Even if we had three years to move everyone from one side
| of the earth to the other and could handle the
| transportation, and then another three years to move them
| back, how are you going to keep them fed? We're just going
| to _double_ our food infrastructure on half of the world?
|
| Where do we house them for several years? We're going to
| double our housing?
|
| How are we going to find all those people jobs to sustain
| them for the several years they're spending on the other
| side of the world?
|
| All those things would have to be part of the logistics
| too. Energy usage. Health care. The list goes on.
|
| It would be a logistical and economic upheaval the likes of
| which the world has never seen. It would lead to political
| chaos and massive wars over suddenly incredibly limited
| resources.
|
| Humanity would survive, but a lot of people wouldn't. It
| wouldn't be a question of logistics, but a complete and
| increasingly violent reconfiguration of society in all
| spheres.
| __MatrixMan__ wrote:
| Just moving a city or two 100 miles away would be sufficient,
| see: https://news.ycombinator.com/item?id=42864509
|
| Supposing we had a good estimate about time and place, it would
| be similar in scope to evacuating for a hurricane.
| SamBam wrote:
| I don't see why you'd make that assumption.
|
| If we run a simulation forward to, say, Jan 1 2032, our
| uncertainty about where the asteroid will be is not only in,
| let's call it, the X and Y axes, describing a flat circle of
| where the asteroid might be (see [1]), but also in a Z axis.
|
| That is, our uncertainty of where the asteroid will be can be
| described as a 3D shape. And if it's further "behind" or
| "ahead" in its trajectory, then it would be passing through
| Earth's orbit behind or ahead of time.
|
| 1.
| https://en.wikipedia.org/wiki/Torino_scale#/media/File:Apoph...
| gWPVhyxPHqvk wrote:
| Even if we had the infrastructural capacity to move hundreds of
| millions or billions of people for that amount of time (how
| many airplanes would you need? where would they all stay?) the
| political considerations would never be feasible. Think if the
| asteroid would hit Central America/Mexico, and think of the
| politics of moving them further north into North America.
| pchristensen wrote:
| XCKD has a grim and humorous breakdown of the logistics of
| moving billions of people: https://what-if.xkcd.com/8/
|
| Spoiler: It's an XKCD What If, so lots and lots of people die.
| giantg2 wrote:
| I suppose the dust cloud from impact could take care of global
| warming for us, assuming it impacts land.
| ainiriand wrote:
| Do not panic, I've rolled a 1d100 and got a 42, we are safe.
| colonial wrote:
| Perhaps this would be a good opportunity to test out asteroid
| deflection technologies? We've got multiple orbital refueling
| architectures (New Glenn, Starship...) slated to come online in
| the next few years, so it should be easier to pack more oomph.
| FooBarBizBazz wrote:
| Just over half of Castle Bravo. Not the end of the world. And the
| Earth's surface is 71% water.
| 2OEH8eoCRo0 wrote:
| Doesn't sound like a huge problem unless we get the size of the
| asteroid wrong. Won't we have a year or more of notice on where
| and when it will impact? Plenty of time to evacuate in a worst
| case scenario.
|
| When there are hurricanes there are often holdouts that don't
| abide by the evacuation order. I wonder if there would be
| holdouts if an asteroid were coming.
| retrocryptid wrote:
| 2024 YR4 isn't that great of a name. I'm guessing the discoverer
| gets to name it. Is there a more human-friendly name?
| jebarker wrote:
| Bookmarked - I don't want to miss a thing.
| ssalazars wrote:
| I see what you did there :)
| Valakas_ wrote:
| By then the singularity will have been achieved.
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