[HN Gopher] Interstellar object exploded over Earth in 2014, dec...
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       Interstellar object exploded over Earth in 2014, declassified govmt
       data reveal
        
       Author : DemiGuru
       Score  : 141 points
       Date   : 2022-04-11 18:46 UTC (4 hours ago)
        
 (HTM) web link (www.livescience.com)
 (TXT) w3m dump (www.livescience.com)
        
       | spdustin wrote:
       | Scientists also detected a meteor particle that appears to have
       | been _extragalactic_ , with a 300km/s (671,081mph) entry
       | velocity...in 2007!
       | 
       | https://link.springer.com/article/10.1134/S1990341307040013
        
       | dustingetz wrote:
       | Is the probability of this event not equal to zero then?
        
         | spuz wrote:
         | The paper estimates objects of these size should hit Earth at
         | least once per decade. The database goes back to 1988 so there
         | might even be one or two others in there waiting to be
         | detected.
        
       | paxys wrote:
       | Tiny meteorite (1.5 feet across) enters Earth's atmosphere and
       | burns up. What is so remarkable about this? Doesn't this happen
       | like every day?
        
         | DocTomoe wrote:
         | The interesting aspect is "interstellar" (=from outside the
         | solar system) instead of just "interplanetary", which would
         | imply an origin within the solar system.
         | 
         | Stuff from outside is a lot rarer.
        
         | mikeyouse wrote:
         | Nearly all meteorites are from the asteroid belt --
         | interstellar origin is the interesting thing here.
        
         | makerofspoons wrote:
         | Meteors from our own solar system impact the atmosphere every
         | day. One estimate for the frequency of an interstellar meteor
         | hitting Earth is about once per decade:
         | https://www.forbes.com/sites/brucedorminey/2019/04/17/inters...
        
       | criddell wrote:
       | Why was this classified in the first place?
        
         | eesmith wrote:
         | From the linked-to Vice article at
         | https://www.vice.com/en/article/dyp9ez/secret-government-inf...
         | 
         | > Some of the sensors that detect fireballs are operated by the
         | U.S. Department of Defense, which uses the same technologies to
         | monitor the skies for nuclear detonations. As a result, Siraj
         | and Loeb couldn't directly confirm the margin of error on the
         | fireball's velocity.
        
           | criddell wrote:
           | I didn't follow all the links, so thanks for pointing out
           | that one in particular. I think it's actually a better write
           | up.
        
       | sneak wrote:
       | The solar system is huge, and earth is really really tiny. For
       | this to have happened means that it is likely to happen again,
       | which suggests that there is a large amount of crap out there
       | blazing through interstellar space, any sufficiently large piece
       | of which could be a civilization-ending projectile.
       | 
       | We need better detection and defenses. And another planet. ASAP.
        
       | Ancalagon wrote:
       | Wow that's actually incredible. The first confirmed interstellar
       | object impacted earths atmosphere? Really shows how far tech must
       | have come in detecting these events in the last 20 years or so.
       | 
       | Also the coincidence of it impacting earth and not Jupiter or any
       | other planetary body or just wizzing by is blowing my mind. Of
       | course we have more sensors around earth so that makes sense but
       | still. I would have thought we would've seen something similar to
       | Oumououa prior to this.
        
         | elihu wrote:
         | If (presumed) single protons can be considered "objects"
         | there's also the "oh-my-God particle" of 1991.
         | 
         | https://en.wikipedia.org/wiki/Oh-My-God_particle
        
         | sliken wrote:
         | Geologist didn't have many sensors for locating earthquakes,
         | but then several governments became very interested in tracking
         | any nuclear testing and those sames sensors are quite good at
         | tracking earthquakes. So much so that earthquakes can now be
         | tracked in 3D anywhere on the planet, even enough to identify
         | the shape and thickness of the various continental plates.
        
           | FredPret wrote:
           | Sometimes throwing money at something... works
        
         | throwaway0a5e wrote:
         | >The first confirmed interstellar object impacted earths
         | atmosphere?
         | 
         | That's mostly just because we don't notice 1.5ft wide rocks in
         | space unless they do something interesting like hit our
         | atmosphere
        
           | [deleted]
        
       | spuz wrote:
       | Interestingly, the database contains two other objects detected
       | with impact speeds of more than 40km/s including one from
       | 2015-07-04 which an even greater speed than this interstellar
       | asteroid. I wonder why these are not also considered to have
       | interstellar origin? Is it because they were accelerated by the
       | sun before colliding with the Earth? The original paper does not
       | mention whether or not they considered the origins of any other
       | objects from the database.
       | 
       | https://cneos.jpl.nasa.gov/fireballs/
        
       | hirundo wrote:
       | > The object, a small meteorite measuring just 1.5 feet (0.45
       | meter) across,
       | 
       | So a bit too small to hold baby Kal-El.
        
         | TameAntelope wrote:
         | And landed in the ocean, so he'd have drowned.
        
           | fsloth wrote:
           | Unless he's a baby octopus. And years after ... oh dear ...
           | "That is not dead which can eternal lie, And with strange
           | aeons even death may die."
        
             | graywh wrote:
             | or some kind of arthropod and we end up in an Arthur C
             | Clarke novel
        
           | bryanrasmussen wrote:
           | I think Superbaby would have survived.
           | 
           | https://superfriends.fandom.com/wiki/Superbaby
        
           | outworlder wrote:
           | That could have been on purpose and they have gills :)
        
         | fsloth wrote:
         | Except unless he's really tiny and cuddly. Like a baby hamster.
        
       | motoboi wrote:
       | So `Oumuamua was actually the sail, the real probe arriving in
       | 2014? #joke
        
       | peter303 wrote:
       | The Arachnids are bombing Earth. (Starship Troopers)
        
       | betterburnout wrote:
       | I sincerely do not understand the interest of the army to hide
       | the presence of such a small meteorite.
        
         | CamperBob2 wrote:
         | It's not about the meteor, it's about the capacity to detect
         | and track it.
        
           | spockz wrote:
           | So the fact that they release this now means that they have
           | an even better detection and tracking mechanism? Or do they
           | just want others to believe that?
        
             | andrewxdiamond wrote:
             | This info is classified by default usually. And the memo
             | reads as if astrophysicists were asking the government to
             | confirm or deny this specific bit of info for their
             | research.
        
       | d_burfoot wrote:
       | The fact that an interstellar object happened by chance to
       | intersect the earth implies that there are millions of such
       | objects flying through the solar system. Most of them probably
       | fly through and are never seen again. We really need to get
       | better at space operations, so we can either catch one of these
       | objects for further study, or at least figure out a way to build
       | a probe that could follow it out of the system.
        
       | Barrin92 wrote:
       | >The possibility of getting the first piece of interstellar
       | material[...]
       | 
       | It's very likely that there's interstellar material already on
       | earth from before we were able to detect the impact though,
       | right? Question for the astrophysicists, is there something in
       | the composition of objects that can tell us if something is
       | interstellar in origin?
        
       | marktangotango wrote:
       | > The object, a small meteorite measuring just 1.5 feet (0.45
       | meter) across, slammed into Earth's atmosphere on Jan. 8, 2014,
       | after traveling through space at more than 130,000 mph (210,000
       | km/h)
       | 
       | Can anyone say what percentage of the speed of light that is?
        
         | [deleted]
        
         | [deleted]
        
         | skissane wrote:
         | About 0.02%
        
         | dkural wrote:
         | ~%0.02 the speed of light. So less one in five thousandth the
         | speed of light.
        
         | Red_Leaves_Flyy wrote:
         | 130,000 /
         | 
         | Speed of light: 670,616,629mph
         | 
         | = 0.00019385144% the speed of light
        
           | [deleted]
        
           | dkural wrote:
           | The ratio is not a percent. For example, 1/100 = 0.01 = 1% -
           | i.e. NOT 0.01% So you would get 0.019385144% speed of light
           | in your calculation.
        
         | pif wrote:
         | You can.
        
       | kstrauser wrote:
       | Real answer:
       | 
       | I absolutely love being alive right now. A Higgs boson! Confirmed
       | objects from outside our solar system! A real life picture of a
       | black hole! We're just at the start of being able to learn these
       | things, and it's getting better by the year. I love it.
       | 
       | Conspiracy answer:
       | 
       | The alien probe launched 10,000 years ago just determined that
       | either:
       | 
       | 1) Our atmosphere is sufficiently thick to cause the object to
       | disintegrate over seconds instead of instantaneously, meaning
       | there's enough raw gaseous material to be interesting, or
       | 
       | 2) We have an active defense system, meaning the local
       | inhabitants are smart enough to be interesting.
       | 
       | In 46 years, when the light reaches its origin around 26
       | Draconis, observations will be recorded, reports will be filed,
       | and plans will be made.
        
         | shakezula wrote:
         | > In 46 years, when the light reaches its origin around 26
         | Draconis, observations will be recorded, reports will be filed,
         | and plans will be made.
         | 
         | This gives me Douglas Adams vibes, thinking about an alien
         | species posting plans to invade Earth. "The plans were on
         | display for months" [1]
         | 
         | [1]: https://www.goodreads.com/quotes/40705-but-the-plans-were-
         | on...
        
           | kingofpandora wrote:
           | That quote is about planning a terrestrial road.
           | 
           |  _This quote_ is about planning an interstellar invasion:
           | https://www.goodreads.com/quotes/5942504-the-mighty-ships-
           | to...
        
           | drewzero1 wrote:
           | It especially reminds me of the Grebulons from the
           | final^H^H^H^H^Hfifth book in the series, whose ships computer
           | was damaged in transit, corrupting the mission directive and
           | the memories of the crew. All they could figure out was that
           | they should monitor the earth from a safe distance, so they
           | set up a base on the tenth planet Rupert and watched earth TV
           | all day.
        
           | kstrauser wrote:
           | "Well, crud. The survey showed that the shortest route isn't
           | completely clear."
           | 
           | "Should we report this?"
           | 
           | "You really want to do all that paperwork?"
           | 
           | "Bulldozer it is."
        
             | drewzero1 wrote:
             | "Do you have any idea how much damage this bulldozer would
             | suffer if I let it roll right over you?"
        
         | EthanHeilman wrote:
         | Sending probes is dangerous. You never know who is going to
         | capture it and figure out where it was sent from. Conclusion:
         | make deniable self-destructing probes.
         | 
         | 1. Send probe to star system slow enough to be random
         | interstellar rock on a collision course with planetary body,
         | 
         | 2. it collects data as it approaches body,
         | 
         | 3. then have it self-destruct in the atmo destroying all
         | technology and information in the probe. Use the energy from
         | the destruction to send a message back on a wide cone that can
         | be intercepted.
        
           | teraflop wrote:
           | Sadly, the combination of "wide cone" and "detectable from
           | light-years away" implies some fairly prohibitive energy
           | requirements.
        
           | [deleted]
        
         | dleslie wrote:
         | (2) is more fun, and so I will actively entertain it while
         | accepting that (1) is more likely to be true.
        
         | gleenn wrote:
         | Could you imagine trying to aim something at a moving planet
         | from light years away and while also shooting it at that speed
         | and not having potential a huge number of things affect it's
         | trajectory via gravity? I love the conspiracy theory, but
         | unless it could course-correct during flight, the odds seem
         | insanely low for it to be a alien test probe
        
           | meetups323 wrote:
           | If I was an alien engineer trying to aim something at a
           | moving planet light years away while also shooting it at that
           | speed and having a huge number of things affect it's
           | trajectory via gravity, I'd make it course-correct during
           | flight.
        
             | ffhhj wrote:
             | "The navigation stage was released about Jupiter, as
             | planned. They will ask for centuries who threw that rock,
             | bhahaharaH!"
        
             | starwind wrote:
             | You can go a step further. Use a computer vision algorithm
             | to find planets, and then do some spectroscopy to identify
             | planets with water in their atmosphere. Course correct to
             | aim at one of those planets
        
           | mrfusion wrote:
           | Why are we assuming it couldnt course correct?
        
             | gleenn wrote:
             | They said it looked like a comet, not a rocket, it was very
             | small in size.
        
           | nonameiguess wrote:
           | This is the plot of the Expanse books. Ancient alien
           | civilization loads a rock with nano-computers that take over
           | self-replicating molecules on planets with life to build
           | stuff, aim it at Earth two billion years ago, but it never
           | makes it because Saturn captures it and it becomes the moon
           | Phoebe instead.
        
           | kstrauser wrote:
           | Well, they're cleverer than us. They probably just plugged
           | the numbers into the n-body equation they teach in their
           | junior high schools.
           | 
           | Also:
           | 
           | - The ion thrusters were small enough to completely
           | disintegrate on impact/reentry.
           | 
           | - Oumuamua was the mother ship, clearly.
        
             | willis936 wrote:
             | Or used their quantum computers with trillions of qBits to
             | be confident of the trajectory to the limit of their
             | sensing ability.
        
               | lokimedes wrote:
               | It was no disintegration at all, merely a thermochemical
               | nanomultiplication catalyst that relied on aerobreaking
               | to generate 10^14 quantum entangled shards of spy drones.
               | These are now permeating all multi-celled organisms,
               | which they have adapted as co-processors. They rely on
               | quantum-entanglement synchronized gravitational wave
               | induction for home-world communication, but can fall back
               | to planet-wide baseline interferometry due to the
               | entangled nature of their origin.
        
           | drexlspivey wrote:
           | Maybe they launched millions of those things
        
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