[HN Gopher] Astronomers discover 3I/ATLAS - Third interstellar o...
___________________________________________________________________
Astronomers discover 3I/ATLAS - Third interstellar object to visit
Solar System
Minor Planet Electronic Circular:
https://minorplanetcenter.net/mpec/K25/K25N12.html
Author : gammarator
Score : 270 points
Date : 2025-07-03 03:19 UTC (19 hours ago)
(HTM) web link (www.abc.net.au)
(TXT) w3m dump (www.abc.net.au)
| ordu wrote:
| Judging by how humanity didn't see any of those for millennia and
| now three in just several years, I can propose two hypotheses:
|
| 1. Astronomers became good enough to notice them 2. These rocks
| are first in an incoming flood of such objects, the Universe
| decided to destroy humanity.
| em3rgent0rdr wrote:
| hah! Yeah the title "Third Interstellar Object Discovered"
| needs to be changed to be more like "Third Discovery of an
| Interstellar Object"
| noduerme wrote:
| I love this. But I can't help imagining the conversation on
| some remote South Pacific island going like this:
|
| "Third cargo chest discovered"
|
| "Maybe they've been sailing by here already for a long time
| and we just didn't notice."
| haiku2077 wrote:
| 3. After we found the first one by chance we started looking
| for more objects outside the solar system's orbital plane
| eesmith wrote:
| This object is near the solar system's orbital plane - far
| closer than Halley's comet, for example.
|
| People have searched off the orbital plane for a long time,
| if only to find new comets.
|
| This object was found by ATLAS, the Asteroid Terrestrial-
| impact Last Alert System. The project goal is to identify
| near-earth asteroids, evaluate the risk they might impact the
| Earth, and alert others if impact is predicted.
|
| The project started in 2015, two years before `Oumuamua. It
| was not made specifically to find interstellar objects
| transiting the solar system.
| metalman wrote:
| un-nervingly near the orbital plane, as the depiction shows
| the object passing just above, on approach, and juct below,
| on departure, of the orbital plane of mars given the low
| relative speed of these objects so far, we can define them
| as extra solar, something exra galactic could be moveing at
| fractional light speed relative to us and be almost
| impossible to see and track unless it was realy big and
| close, and as there are confirmed exra galactic stars, it
| is not conjecture to to then include rouge planets and
| asteriods ,etc in the list of signatures to be looking for,
| and perhaps dismissed from previous data as bieng equipment
| artifacts or noise.
| dotnet00 wrote:
| I get that you're joking, but I wonder if it could just be that
| we happen to be passing through some sort of interstellar
| debris cloud.
| tigerlily wrote:
| Get ready for the, uh, Latter Day Late Heavy Bombardment!
| mr_toad wrote:
| Actually we're in a surprisingly sparse area of the galaxy, a
| giant hole in the galaxy created by one (or more) supernova.
|
| https://en.wikipedia.org/wiki/Local_Bubble
| stevedonovan wrote:
| So much for the old thermonuclear ramjet idea....
| kirykl wrote:
| Maybe. The solar system was in this galactic position about
| 250 million years ago (one galactic year) and there was a
| major extinction event around that time
| elchananHaas wrote:
| It's 1. A combination of better telescopes and GPU accelerated
| algorithms for picking out moving objects.
| 9dev wrote:
| > These rocks are first in an incoming flood of such objects
|
| When `Oumuamua flew past, we should have noticed it was a
| passive sensor drone. Now it is too late.
| shiroiuma wrote:
| It's not "the Universe"; it's an alien race that wants to
| destroy us before we become a threat to them.
| belter wrote:
| We are a much bigger threat to ourselves.
| phatskat wrote:
| Yep, the best thing for a race that is (rightfully) worried
| about our aggressiveness is to wait it out.
| lynx97 wrote:
| Came here to say that. Best to just wait and let history
| take its course.
| nandomrumber wrote:
| Or launch an attack fleet, only to later, due to an error
| in a scaling factor, have the entire fleet unknowingly
| swallowed by a small dog.
| belter wrote:
| https://youtu.be/smwd8b0ycBg
| dguest wrote:
| It's more complicated than that.
|
| Benevolent aliens are planting incompetent people in
| positions of power so that we are perpetually on the
| verge of self-annihilation. But this is all to save us
| from the malevolent aliens who would obliterate us if
| they thought we had any chance of survival.
| eb0la wrote:
| I believe #1 is true; but not #2. It's just that those rocks
| are more common than we thought. And we thought they were
| uncommon because we weren't able to spot them... yet.
| polytely wrote:
| Vera Rubin just came online, will will start to do surveys of
| the entire sky every 3 nights, which makes spotting stuff like
| this easier.
|
| https://youtu.be/X3N-DjVXh44
|
| so we are probably gonna notice a lot more of them
| TheBlight wrote:
| We don't know if they're all rocks or not yet.
| slightwinder wrote:
| We hadn't the means to discover them for most of the last
| millennia, so now being good enough is obvious. But the
| question is why now, and not 10 or 20 years ago. It might be
| that we had the ability for a longer time already, but it just
| never "clicked" until now to recognize them. It is also
| possible that we really just got good enough recently. Or even
| that until now, there really were none in the last decade we
| could find, and we are just lucky(?) that now more are coming
| our way.
|
| We might know this better in the next years, depending on
| whether there will now be an explosion of dozen and dozens of
| new interstellar objects discovered, or not. It might be
| another rush, like with exoplanets and local dwarf-planets.
| jerpint wrote:
| I know nothing about this type of data; what does it mean and how
| can it be interpreted as an object ?
| ddahlen wrote:
| This is an announcement from the Minor Planet Center (MPC).
| They are the official international clearing house for
| observations of solar system objects.
|
| The top indicates that the object has two names (this is
| common): 3I/ATLAS = C/2025 N1 (ATLAS)
|
| ATLAS was the telescope that made the discovery.
|
| The list of data are individual observations of the object by
| different telescopes. This observation format has been in use
| for a _long_ time, but is being phased out. A row is meant to
| fit on a single punch card...
|
| These observations are then used to calculate orbits, the MPC
| calculates the orbit as well, but this list of observations is
| also ingested by JPL and their Horizons service.
| ddahlen wrote:
| This one is coming in fast, it has an eccentricity of over 6 with
| the current fits. For point of reference, 1I and 2I have
| eccentricities of 1.2 and 3.3.
|
| Right now it is mostly just a point on the sky, it is difficult
| to tell if it is active (like a comet) yet. If it is not active,
| IE: asteroid like, then the current observations put it somewhere
| between 8-22km in diameter (this depends on the albedo of the
| surface). From what we know, we would expect it to likely be made
| up of darker material meaning given that range of diameters it is
| more likely to be on the larger end. However if it is active,
| then the dust coming off can make it appear much larger than it
| is. As it comes in closer to the sun and starts to warm up it may
| become active (or more active if its already doing stuff).
|
| It will not pass particularly close to any planet. It will be
| closest to the sun just before Halloween this year at 1.35 au,
| moving at 68 km/s (earth orbits at 29-30 km/s). It is also
| retrograde (IE, it is moving in the opposite direction of
| planetary motion), for an interstellar object this is basically
| random chance that this is the case.
|
| Link to an orbit viewer:
| https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=3I&vi...
|
| The next couple of weeks will be interesting for a bunch of
| people I know.
|
| Source: Working on my PhD in orbital dynamics and formerly wrote
| the asteroid simulation code used on several NASA missions:
| https://github.com/dahlend/kete
| noduerme wrote:
| What planets is it passing between?
| ddahlen wrote:
| It is inside jupiter's orbit now, it will come inside Mars
| for a time. It is almost on the plane of the solar system,
| not very inclined.
|
| I linked an orbit viewer above if you want to look.
| Teever wrote:
| > It is almost on the plane of the solar system, not very
| inclined.
|
| Is this also random chance or is there a reason why it's so
| close to the plane of the solar system?
| ddahlen wrote:
| It is also a factor of where our surveys look on the sky.
| A lot of asteroid surveys have biases to look at the
| plane of our solar system (since this is where a lot of
| asteroids are).
|
| It is probably random chance, however there may be some
| biases from where they come from on the sky (I know
| people who work on that, but I don't know much about it).
|
| N=3 does not provide very robust statistics yet, give us
| another decade or two.
| sgt101 wrote:
| We're going to see a lot more of these in the next couple
| of years due to the new Vera C Rubin observatory.
| JumpCrisscross wrote:
| Also the ELT [1], I believe. (Both come online this
| year.)
|
| [1]
| https://en.m.wikipedia.org/wiki/Extremely_Large_Telescope
| cyberlimerence wrote:
| ELT's first light is planned for March 2029.[1] Vera is
| already online I think.
|
| [1] https://www.eso.org/public/announcements/ann25001/
| hermitcrab wrote:
| I can't believe that all those super-intelligent
| astronomers, who spend hours on their own in the dark,
| couldn't come up with a better name than 'Extremely Large
| Telescope'. ;0)
| mcswell wrote:
| I guess they should have SuperSized(tm) it.
| Tuna-Fish wrote:
| At this point, it is tradition.
|
| https://upload.wikimedia.org/wikipedia/commons/c/c5/Compa
| ris...
| defrost wrote:
| Good question, especially given the plane of our solar
| system is almost orthogonal to the greater plane of the
| Milky Way galaxy that contains us.
| rbanffy wrote:
| I would expect most visitors would come from the galactic
| plane.
| noduerme wrote:
| Huh. It looks like on 10/2 it will make its closest pass to
| a planet, Mars, and on that date it also is in a straight
| line with Mars, Mercury and the sun, while Earth and Venus
| are roughly opposite each other. Do you know if this sim
| accounts for solar or martian gravity diverting its
| trajectory?
| ddahlen wrote:
| This orbit visualization uses a simple 2 body
| approximation, so only the sun. This is because unless an
| object has a VERY close approach to a planet the two body
| approximation is more then enough for this style of
| visualization.
|
| I did a full proper n-body integration and it is not
| visually different than this.
| TrainedMonkey wrote:
| From the simulation you linked looks like it is passing
| closeish to the Mars... but I do know that space is big.
| However, I am curious of what would happen if an object of this
| magnitude hit mars at 90km/s.
| ddahlen wrote:
| I would recommend staying on Earth...
| jl6 wrote:
| Assuming it's at the upper range of the size estimate above,
| and of average rocky density, the kinetic energy of the
| impact would be something like a 10 billion megaton nuke.
|
| If we could steer it to hit one of Mars's poles, it might do
| a bit of terraforming for us!
| eesmith wrote:
| Where did my math go wrong? I got about 50,000 megatons.
| Assuming the high-end of 22km and a rocky/metallic density
| of 5000 kg/cubic meter (and assuming it's a cube):
| kinetic energy = 1/2 m v**2 = 1/2 * size * density * v**2
| = 1/2 *(22000 m)**3 * (5000 kg/m**3) * (90 m/s)**2 /
| (4.184E15 J/megaton) = 52,000 megaton
|
| If it's an icy comet then the density is more like 500
| kg/cubic meter, or 1/10th that number.
| nandomrumber wrote:
| 1040 x more energy that the Tsar Bomba.
|
| Or 5-ish Tsar Bomba per country on Earth.
|
| Or 3466 Hiroshima nukes.
|
| Or 17 Hiroshima nukes per country.
| nandomrumber wrote:
| In light of the error in the parent comments math, I
| retract my previous comment and substitute the following
| bit of awkward silence:
|
| ...
| defrost wrote:
| We all make mistakes, as the Dalek said climbing off the
| dustbin.
|
| FWiW .. here's mine (or is it?)
|
| One Tsar Bomba ~ 50 megatonne. One Hiroshima bomb ~ 15
| kilotonne.
|
| One Tsar Bomba ~ 50,000 / 15 ~ 3,333 Hiroshima bombs.
|
| 1,040 x Tsar Bomba ~ 3,466,667 Hiroshima bombs.
| nandomrumber wrote:
| Oops.
|
| Every time I see your username I can't help but say it in
| my mind as Defrost Kelly, some kind of frozen Dr. Leonard
| "Bones" McCoy
| ars wrote:
| 90 m/s?
|
| Way too slow, it's more like 70km/s (or 90) - seems you
| left out a k.
| eesmith wrote:
| Yes, that was my error - thanks!
| perihelions wrote:
| I can not confirm this; the parent calculation is the
| correct one. I can't immediately find what your error
| was. (edit: It's your [km/s]--you wrote [m/s] by
| mistake). (let* ((r ([g (cm -3)] 5))
| (d ([km] 22)) (m (* r (expt d 3)))
| (v ([km (s -1)] 90)) (ke (* 1/2 m (expt v
| 2))) (kg-tnt ([J (kg -1)] 4.2e6)))
| (values (/ ke kg-tnt) (as [megaton] (/ ke kg-
| tnt)))) 5.133857142857142e19 [KG]
| 5.133857142857143e10 [MEGATON]
| eesmith wrote:
| My mistaken use of m/s instead of km/s, in a squared
| term, indeed gives a HUGE difference.
|
| Thanks!
| Voultapher wrote:
| Based on the corrected 90 km/s instead of m/s it should
| be 52 pt (peta-ton) impact.
| eesmith wrote:
| Let's see if I get this math right.
|
| Mauna Loa is about 95,000 km3 in volume says
| https://www.usgs.gov/volcanoes/mauna-kea/science/geology-
| and... . Density of TNT is 1.6g/cm3:
| 95000 km3 * (1000m/km)**3 * 1600 kg/m3 = ~1.5E17 = 150
| pt.
|
| 1/3rd of the mountain in TNT.
|
| Nope, I can't conceive of that much energy.
| nativeit wrote:
| ...and after just a few million years to settle down again,
| we'll be ready to visit blue sky on Mars!
| nandomrumber wrote:
| Would be wild if a sufficiently large object with a lot of
| water and organic molecules hit Mars, ejected a lot of
| material in to Mars' orbit to then go on to form a
| sufficiently large moon that tidally massaged Mars' core to
| cause a dynamo to generate a sufficiently strong magnetic
| field to...
|
| Terraform Mars!
| WithinReason wrote:
| You don't need a magnetic field to terraform Mars, it can
| hold onto an atmosphere without it for 100M years.
| nandomrumber wrote:
| Without a magnetic field, isn't the surface of Mars
| subject to sterilising radiation from Sol?
| cyberax wrote:
| Planetary magnetic field only weakly protects against
| cosmic rays (extra-solar origin).
|
| A thick enough atmosphere will stop pretty much all the
| charged particles from the normal solar radiation.
| jajko wrote:
| If it would be so bad, Earth's polar regions
| (experiencing aurora borealis) would be inhabitable too.
| Earth's magnetic field is not magically neutralizing all
| charged particles from the Sun, just diverts them (some
| maybe away, but many simply towards poles).
|
| And clearly even our mag field (and Sun's heliosphere) is
| not enough to shield us from those crazy cosmic rays.
| noduerme wrote:
| in a somewhat related story, I was on a beach in Costa Rica
| last week, watching some spider monkeys in a palm tree
| trying to whack open small nuts. Just then, an American
| family walked up the beach with two teenage boys. They
| didn't notice the monkeys I was watching. But one of the
| boys grabbed a coconut off the sand and became determined
| to break it open with a rock in front of his parents. So
| watching the monkeys and the boy simultaneously, I had the
| distinct feeling of how slowly evolutionary, let alone
| geological, processes actually move.
| nandomrumber wrote:
| Haha, cool, that gave me a chuckle :)
|
| "We'll be saying a big hello to all intelligent lifeforms
| everywhere and to everyone else out there, the secret is
| to bang the rocks together, guys." - The Hitchhikers
| Guige to the Galaxy, Douglas Adams
| Angostura wrote:
| Gag Halfront, wasn't it?
| goopypoop wrote:
| Max Quordlepleen
| hermitcrab wrote:
| Nice story.
|
| But are you implying that we are somehow more evolved
| than the monkeys? Both the human and the monkey in the
| story have evolved for the same amount of time since our
| last common ancestor.
| MarkusQ wrote:
| That argument always struck me as vacuous. Dump a barrel
| of ball bearings on the top of a craggy hill. Wait as
| they all bounce around, some getting stuck in local
| minima and some bouncing over obstacles and covering
| large distances.
|
| Would you claim that they all traveled the same distance
| because they all traveled for the same amount of time?
|
| Evolutionary space is very high dimension, which makes
| the argument that just projecting onto the (1d) time axis
| is misleading even stronger.
| hermitcrab wrote:
| I'm not sure more/less evolved is a meaningful concept in
| Darwinian terms. Organisms have a level of fitness for
| their environment. Perhaps you are talking about cultural
| evolution?
| nandomrumber wrote:
| Do not we humans and those monkeys largely share the same
| environment?
|
| Which one is more numerous, less prone to natural
| forcings?
| belter wrote:
| What is easier? Not mess up this planet, or Terraform Mars?
| olvy0 wrote:
| Username checks out.
| malfist wrote:
| I don't know. Have you seen humanity? I think teraforming
| another planet is probably easier than not fucking up
| this one
| bee_rider wrote:
| Belter, our future is in orbital habs. Going downwell is
| for tourism and archaeology.
| dotnet00 wrote:
| Can you walk and chew gum?
| irrational wrote:
| It's not worth doing because it is easier, but because
| all of our eggs are in one basket (planet). We know of
| disasters that can wipe out almost all life on a single
| planet. Of course, there are also disasters that can wipe
| out all life in one star system (and one region of the
| Galaxy). So, ideally we need to colonize many worlds in
| many different parts of the Galaxy, but baby steps. Step
| one is to have a sustainable population on multiple
| moons/planets/stations of this star system before we jump
| to other star systems.
| ReptileMan wrote:
| Absolutely nothing. Way too small and slow.
| nativeit wrote:
| How fast does something need to be traveling before you'd
| consider it to be fast? It probably weighs as much as a
| city and it is traveling tens of times faster than a high-
| velocity bullet.
| ReptileMan wrote:
| It is of the same caliber as the dinosaur ending
| meteorite. The planet barely shrugged from it. There is
| suspicion that something the size of pluto has already
| hit mars once upon a time. And it is way more massive
| than this speck of cosmic dust.
| belter wrote:
| Are you able to calculate whether, by any chance, it will come
| close to any of the NASA probes around Jupiter, Mars, Venus,
| etc...? What is its closest approach to the JWST?
| ddahlen wrote:
| The closest it will come is Mars, but when I say close these
| are quite literally astronomical distances, about 0.2 au from
| Mars. This is about 75x further than the moon is from the
| Earth.
|
| If it is an inactive rock, then we will not see it as any
| more than a point of light during its visit.
| tvickery wrote:
| I know it's incredibly, vanishingly unlikely but what would
| happen if an object with these characteristics smacked into
| Earth?
| _joel wrote:
| The end, unless you're a small proto-mammal ;).
|
| An object (depending on consistency) of about 100m is enough
| to wipe out a city and do enough damage to the environment.
| Something of 8-20km is in the same category as what wiped out
| the dinosaurs (10-15km).
| padjo wrote:
| It's going at 68km/s so I think even microbial life could
| be in trouble.
| _joel wrote:
| You could very well be right!
| MaxikCZ wrote:
| 8-22km at interstellar speeds? Probably total extinction
| level.
| ra wrote:
| With this much mass and velocity - it would smash the planet,
| rupturing the entire crust at the very least.
|
| No matter how infinitesimally small the probability - the
| universe is infinite, and so it probably will happen.
|
| i3 is much bigger than the Chicxulub asteroid that ended the
| Cretaceous period (and extinct all non-avian dinosaurs).
| TMEHpodcast wrote:
| Closest approach will be October 29, 2025. It's currently
| passing Jupiter's orbit. I'm amazed that even at this speed it
| will take that long to get here.
|
| "Space is big. You just won't believe how vastly, hugely, mind-
| bogglingly big it is." ~Douglas Adams
| bee_rider wrote:
| Sometimes it is hard to think of big space is, especially
| because we tend to do that while sitting around inside (this
| is where we have most of our thoughts, after all). Of course
| space distances are nothing like the distances inside our
| rooms, no frame of reference.
|
| Instead, go out to the ocean on a clear day, and observe how
| absurdly vast the ocean is. Just ocean, as far as you can
| see. Look around and realize you've gained absolutely nothing
| in terms of comprehending the vastness of space, to which the
| difference between your room and the most sweeping views on
| Earth are just totally insignificant.
| GolfPopper wrote:
| The single best depiction of the Solar System to help grok
| size and distance is Josh Worth's "If the Moon were only 1
| pixel":
|
| https://www.joshworth.com/dev/pixelspace/pixelspace_solarsy
| s...
| rickydroll wrote:
| An even better visualization of the size of the Solar
| System. It shows traveling from the Sun out to forever at
| the speed of light. Be prepared to spend hours watching
| the paint dry. I suspect traveling in space will be like
| war, long periods of boredom punctuated by brief moments
| of sheer terror.
|
| https://www.youtube.com/watch?v=1AAU_btBN7s
|
| [edit] arrgh. brain spaz forgot to put in the URL
| tambeb wrote:
| I also like this solar system model from NASA,
| https://science.nasa.gov/learning-resources/how-big-is-
| the-s....
|
| They compare it to a US football field.
|
| _" On this scale, the Sun, by far the largest thing in
| our solar system, is only a ball about two-thirds of an
| inch (17 millimeters) in diameter sitting on the goal
| line -- that's about the width of a U.S. dime coin. ...
|
| The inner planets -- Mercury, Venus, Earth and Mars --
| are about the size of grains of sand on a football field
| scale. They would be dwarfed by a typical flea, which is
| about 3 millimeters long.
|
| Closest to the goal line is Mercury, just under a yard
| from the end zone (.8 yards to be specific). ... At this
| scale, Mercury's diameter would be scarcely as large as
| the point of a needle.
|
| Venus is next. It is 1.4 yards from the end zone. ...
|
| On to Earth, sitting pretty on the 2-yard line. ...
|
| Mars is on the three-yard line of our imaginary football
| field. ...
|
| Jupiter remains pretty close to our end zone on the
| 10.5-yard line. ...
|
| Saturn is on the field at 19 yards from the goal line.
| ...
|
| Uranus ... is about 38 yards from our end zone.
|
| Neptune is where things start to get way out. It is 60
| yards from our solar goal line on the imaginary football
| field. ...
|
| Tiny Pluto is much closer to the opposing team's end
| zone. It's about 79 yards out from the Sun ...
|
| On this scale, our little friend Voyager 1 has left the
| game and is well out in the stadium parking lot or
| beyond."_
| Archelaos wrote:
| I like planetary trails, where the orbits of the planets
| (or other celestrial objects) are proportionally reduced
| and placed in the landscape.
|
| For example, this image from a park in Halle (Germany)
| shows the inner solar system: https://dubisthalle.de/wp-
| content/uploads/2023/06/Planetenwe... -- but one has to
| walk 500 meters to reach Pluto.
|
| The German Wikipedia has quite a long list of planetary
| trails: https://de.wikipedia.org/wiki/Planetenweg
| goopypoop wrote:
| No no no no no.
|
| "If life is going to exist in a Universe of this size, then
| the one thing it cannot afford to have is a sense of
| proportion." -DNA
| madmask wrote:
| And the horizon you see standing on the beach is just about
| 5km or 3 miles away!
| synlatexc wrote:
| Primo Levi wrote a short story [1] about this. Our
| words/measurements are inadequate when tasked with
| describing the cosmos.
|
| [1]
| https://www.newyorker.com/magazine/2007/02/12/a-tranquil-
| sta...
| RcouF1uZ4gsC wrote:
| > Source: Working on my PhD in orbital dynamics and formerly
| wrote the asteroid simulation code used on several NASA
| missions:
|
| This is one of the big reasons I love HN
| TMEHpodcast wrote:
| I agree and I'm old enough to remember when Reddit was like
| this
| hermitcrab wrote:
| From the first link I get:
|
| "specified object was not found"
|
| What do you mean by 'active' here - has a plume?
| snowwrestler wrote:
| I found it by searching an alternate designation:
|
| C/2025 N1
|
| Edit: does this link work?
|
| https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=C%2F2.
| ..
| slwvx wrote:
| Yes, thanks!
| ilamont wrote:
| Thanks for sharing this info. Does "eccentricity" refer to the
| orbit, or the shape of the object?
|
| For 'Oumuamua in 2017, some method was used to determine its
| shape, which is (apparently) remarkably elongated. Is it
| possible to determine the elongation of the new object?
|
| https://science.nasa.gov/solar-system/comets/oumuamua/
| treyd wrote:
| Eccentricity refers to the shape of the orbit, derivable from
| the highest and lowest distances in the orbit of the orbiting
| body (there's actually a bunch of ways to calculate it that
| are mathematically equivalent). It's related to modeling
| orbits as conic sections. An eccentricity of 0 is a perfect
| circle, <1 is a normal elliptical orbit, >=1 is an escaping
| trajectory.
|
| For example, Earth's orbit around the sun is ~0.0167, Pluto's
| is 0.248.
| Tuna-Fish wrote:
| We don't have enough data of the object yet to say basically
| anything at all about its shape.
| bbor wrote:
| Thanks for sharing your expertise! What really bends my mind is
| the relative speeds involved. Reddit's /r/space has a great
| visual[1] which depicts it as basically going straight through
| our solar system, only bending slightly as it passes Sol. This
| is only possible if the object moving at 68 km/s is also moving
| _sideways_ at 230 km /s so as to match our galactic orbit, and
| moving _up_ at a mind-boggling 600 km /s (relative to CMB).
| This is all basic stuff of course, but something about having
| the object actually pass by us is making it more real than
| usual...
|
| Hell, maybe it's only orbiting the galaxy at a leisurely 160
| km/s, and from its perspective we're a spinning disc of chaos
| zipping past it for the first time in a few million years! I
| don't even know how I would start to analyze its orientation in
| relation to the galactic center, but I'll be keeping this as my
| little "headcannon" until proven wrong, that's for sure.
|
| [1]
| https://www.reddit.com/r/space/comments/1lpw4as/new_interste...
| somenameforme wrote:
| Getting a "specified object not found" on the orbit viewer.
| zeristor wrote:
| I am assuming with that the newly commissioned Vera Rubin
| telescope should start finding a lot more of these.
| belter wrote:
| https://en.wikipedia.org/wiki/3I/ATLAS
| lionkor wrote:
| Don't look up
| Validark wrote:
| Ahhhhhh!!!!!!!!!!!
| tomhow wrote:
| We updated the URL to the ABC news report as it's more
| understandable to lay people, at least those like me. If someone
| finds a better report, let us know and we'll be happy to update
| it.
|
| The original URL was
| https://minorplanetcenter.net/mpec/K25/K25N12.html, which I've
| included in the header.
| rjinman wrote:
| The more interstellar objects we find that resemble comets, the
| weirder Oumuamua is.
| LeoPanthera wrote:
| The Ramans do everything in threes.
| moritonal wrote:
| Thank you! Finally a good Rama reference in the wild.
| TheOtherHobbes wrote:
| Maybe. I think it's more likely that an alien probe - assuming
| there are aliens and they fly probes - would be the size of a
| cubesat, and we wouldn't even notice it.
|
| Perhaps Oumuamua was the mothership and the solar system is now
| swarming with cubesats we're not noticing.
| hermitcrab wrote:
| >I think it's more likely that an alien probe - assuming
| there are aliens and they fly probes - would be the size of a
| cubesat
|
| Or maybe the size of a sub-atomic particle, as in the sci-fi
| Novel 'The 3 body problem'.
|
| https://three-body-problem.fandom.com/wiki/Sophons
| le-mark wrote:
| I really hope someone sends a probe to catch Omaumau. When
| Starship is flying regularly it should be doable, just barely.
| nativeit wrote:
| It's news to me that Starship flying is doable.
| hermitcrab wrote:
| Can we get Musk to pilot it?
| russdill wrote:
| The chances that it's a rare type of interstellar object are
| incredibly small.
| carlsborg wrote:
| The great filter: light years of travel needed by detection
| probes.
| martinclayton wrote:
| In a thread elsewhere I saw "Interstellar Objects in the Solar
| System: 1. Isotropic Kinematics from the Gaia Early Data Release
| 3" (https://arxiv.org/pdf/2103.03289) mentioned.
|
| In there, one estimate of the number of these objects is
| Nisc <~ 7.2 x 10-5 AU-3
|
| Which (my, probably wrong, calc) implies roughly one inside the
| orbital volume at the radius of Saturn's orbit at any time.
| fouronnes3 wrote:
| The first two were used up, empty deceleration stages of a giant
| alien spaceship, discarded during interstellar cruise while the
| rest of the assembly kept burning for its years long deceleration
| from relativistic speeds. This is the main ship.
| whycome wrote:
| expand this into a sci Fi novella please
| jcfrei wrote:
| If this new 8m diameter telescope already provides us with so
| many new discoveries then I can't wait until the ELT with 39m
| diameter goes online.
| sapiogram wrote:
| ELT will not discover many new objects, it's built to do deeper
| followup observations of known targets. On the other hand, Vera
| Rubin was designed to be a survey telescope, repeatedly imaging
| the entire night sky to discover new objects. It will not do
| targeted observations, or at least very few.
| aeve890 wrote:
| >Vera Rubin was designed to be a survey telescope, repeatedly
| imaging the entire night sky to discover new objects.
|
| The entire _southern hemisphere_ night sky right?
| sapiogram wrote:
| Yeah, not the entire northern sky at least. It's located
| only 30 degrees south though, so its coverage will be
| pretty damn good.
| andrewstuart wrote:
| They're always coming through.
|
| The solar system is an interstellar highway.
|
| Chariots Of The Gods, man.
|
| But seriously, why would interstellar objects come towards our
| solar system?
|
| It seems strange. Does gravity do that?
|
| If there's two within ten years then there has to be a veritable
| swarm of these things traveling between the stars - is that right
| or wrong?
| Jyaif wrote:
| A very rough calculation would suggested that the cylinder that
| goes from our solar system to Proxima Centauri contains 5000
| similarly sized objects moving at the same speed:
|
| 1 object crossing the solar system plane every 5 years at
| 60km/s
|
| +
|
| Proxima Centauri is approximately 5 light years away
|
| =>
|
| there are `speed of light / 60km/s` objects in the cylinder.
| hermitcrab wrote:
| Objects can get flung out of solar systems when they pass close
| to large objects. Similar to how spacecraft get gravity
| assists.
| alganet wrote:
| > But seriously, why would interstellar objects come towards
| our solar system?
|
| Why wouldn't they?
| coolspot wrote:
| Because to go through plane like that they need to match our
| solar system speed relative to galaxy.
| alganet wrote:
| Universe is big and full of random small rocks floating
| around everywhere.
|
| Why should I believe some object was _intentionally_ thrown
| here? Maybe it is just one of those random rocks.
| andrewstuart wrote:
| Because space is big. Really really big.
| alganet wrote:
| The ocean is big compared to a fish, but I can still find
| fish in it quite easily.
|
| There's nothing statistically weird about these
| interstellar objects.
| andrewstuart wrote:
| Are we going to be able to get a close look at this?
| russdill wrote:
| Not really, the sun will be in a rather inconvenient position.
| artur_makly wrote:
| If it were to come right for us, what do we have today to stop it
| (if at all) ?
| atrus wrote:
| If we're just talking about interstellar objects, and assuming
| a decent lead time (not oh hey it's going to hit in 3 days),
| it's probably easier to prevent it from hitting us since it's
| most likely just passing through. You'd only need to give it a
| small enough nudge to have it miss a smidge. That's something
| we're more than capable now of doing, and have done.
| coolspot wrote:
| > That's something we're more than capable now of doing, and
| have done.
|
| You're very optimistic about our ability to divert 22km-
| diameter object moving at 70km/s .
|
| DART smashed 680kg payload into a 780m-diameter Didymos
| changing its orbit.
| russdill wrote:
| If this object were coming straight for Earth there would be
| pretty much nothing we could do to avoid a collision. Luckily
| the chances of such a collision are enormously small. We are
| fortunately bringing more resources on line to find such
| objects sooner.
| renrutal wrote:
| It would be neat if we could take a hitchhike with it.
|
| Probably only Project Orion would be able to catch up to its
| current 60kms/s speed by October.
| Klathmon wrote:
| Given it's passing retrograde (is that even the right way to
| say that?), would that make it easier to catch up and
| intercept?
|
| Assuming you don't want to do anything but fly by or smash into
| it
| isx726552 wrote:
| Wow. The 2019 novel "The Last Astronaut" hypothesized about a
| fictional interstellar object coming into the solar system,
| called "2I" in the novel for short, but back here in real life,
| we're already up to 3I.
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