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.
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
TMEHpodcast 13 hours ago [-]
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 11 hours ago [-]
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 10 hours ago [-]
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":
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.
"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."
synlatexc 3 hours ago [-]
Primo Levi wrote a short story [1] about this. Our words/measurements are inadequate when tasked with describing the cosmos.
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?
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 7 hours ago [-]
We don't have enough data of the object yet to say basically anything at all about its shape.
TrainedMonkey 18 hours ago [-]
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.
nandomrumber 17 hours ago [-]
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!
noduerme 17 hours ago [-]
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 17 hours ago [-]
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 12 hours ago [-]
Gag Halfront, wasn’t it?
goopypoop 10 hours ago [-]
Max Quordlepleen
hermitcrab 10 hours ago [-]
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 9 hours ago [-]
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 8 hours ago [-]
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 4 hours ago [-]
Do not we humans and those monkeys largely share the same environment?
Which one is more numerous, less prone to natural forcings?
WithinReason 17 hours ago [-]
You don't need a magnetic field to terraform Mars, it can hold onto an atmosphere without it for 100M years.
nandomrumber 17 hours ago [-]
Without a magnetic field, isn’t the surface of Mars subject to sterilising radiation from Sol?
cyberax 17 hours ago [-]
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 16 hours ago [-]
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.
belter 12 hours ago [-]
What is easier? Not mess up this planet, or Terraform Mars?
bee_rider 11 hours ago [-]
Belter, our future is in orbital habs. Going downwell is for tourism and archaeology.
irrational 9 hours ago [-]
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.
malfist 12 hours ago [-]
I don't know. Have you seen humanity? I think teraforming another planet is probably easier than not fucking up this one
dotnet00 10 hours ago [-]
Can you walk and chew gum?
olvy0 12 hours ago [-]
Username checks out.
jl6 18 hours ago [-]
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!
nativeit 12 hours ago [-]
…and after just a few million years to settle down again, we’ll be ready to visit blue sky on Mars!
eesmith 17 hours ago [-]
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.
perihelions 17 hours ago [-]
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* ((ρ ([g (cm -3)] 5))
(d ([km] 22))
(m (* ρ (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 16 hours ago [-]
My mistaken use of m/s instead of km/s, in a squared term, indeed gives a HUGE difference.
Thanks!
Voultapher 7 hours ago [-]
Based on the corrected 90 km/s instead of m/s it should be 52 pt (peta-ton) impact.
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 17 hours ago [-]
90 m/s?
Way too slow, it's more like 70km/s (or 90) - seems you left out a k.
eesmith 16 hours ago [-]
Yes, that was my error - thanks!
ddahlen 18 hours ago [-]
I would recommend staying on Earth...
ReptileMan 17 hours ago [-]
Absolutely nothing. Way too small and slow.
nativeit 12 hours ago [-]
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 11 hours ago [-]
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.
somenameforme 7 hours ago [-]
Getting a "specified object not found" on the orbit viewer.
tvickery 13 hours ago [-]
I know it’s incredibly, vanishingly unlikely but what would happen if an object with these characteristics smacked into Earth?
ra 12 hours ago [-]
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).
_joel 13 hours ago [-]
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).
No, I can’t really imagine what that means, either.
padjo 12 hours ago [-]
It’s going at 68km/s so I think even microbial life could be in trouble.
_joel 11 hours ago [-]
You could very well be right!
MaxikCZ 13 hours ago [-]
8-22km at interstellar speeds? Probably total extinction level.
noduerme 19 hours ago [-]
What planets is it passing between?
ddahlen 19 hours ago [-]
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.
noduerme 17 hours ago [-]
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 15 hours ago [-]
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.
Teever 18 hours ago [-]
> 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 18 hours ago [-]
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 17 hours ago [-]
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 16 hours ago [-]
Also the ELT [1], I believe. (Both come online this year.)
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)
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 13 hours ago [-]
I would expect most visitors would come from the galactic plane.
bbor 8 hours ago [-]
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.
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 17 hours ago [-]
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.
RcouF1uZ4gsC 10 hours ago [-]
> 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 10 hours ago [-]
I agree and I’m old enough to remember when Reddit was like this
ordu 19 hours ago [-]
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.
polytely 14 hours ago [-]
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.
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
tigerlily 15 hours ago [-]
Get ready for the, uh, Latter Day Late Heavy Bombardment!
slightwinder 8 hours ago [-]
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.
eb0la 17 hours ago [-]
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.
TheBlight 11 hours ago [-]
We don't know if they're all rocks or not yet.
shiroiuma 19 hours ago [-]
It's not "the Universe"; it's an alien race that wants to destroy us before we become a threat to them.
belter 18 hours ago [-]
We are a much bigger threat to ourselves.
phatskat 17 hours ago [-]
Yep, the best thing for a race that is (rightfully) worried about our aggressiveness is to wait it out.
lynx97 17 hours ago [-]
Came here to say that. Best to just wait and let history take its course.
dguest 10 hours ago [-]
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.
nandomrumber 17 hours ago [-]
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.
3. After we found the first one by chance we started looking for more objects outside the solar system's orbital plane
eesmith 18 hours ago [-]
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 ʻOumuamua. It was not made specifically to find interstellar objects transiting the solar system.
metalman 12 hours ago [-]
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.
zeristor 18 hours ago [-]
I am assuming with that the newly commissioned Vera Rubin telescope should start finding a lot more of these.
martinclayton 14 hours ago [-]
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 × 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.
isx726552 6 hours ago [-]
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.
rjinman 16 hours ago [-]
The more interstellar objects we find that resemble comets, the weirder Oumuamua is.
TheOtherHobbes 13 hours ago [-]
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 9 hours ago [-]
>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'.
Thank you! Finally a good Rama reference in the wild.
le-mark 12 hours ago [-]
I really hope someone sends a probe to catch Omaumau. When Starship is flying regularly it should be doable, just barely.
nativeit 12 hours ago [-]
It’s news to me that Starship flying is doable.
russdill 7 hours ago [-]
The chances that it's a rare type of interstellar object are incredibly small.
hermitcrab 9 hours ago [-]
Can we get Musk to pilot it?
jerpint 19 hours ago [-]
I know nothing about this type of data; what does it mean and how can it be interpreted as an object ?
ddahlen 18 hours ago [-]
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.
artur_makly 11 hours ago [-]
If it were to come right for us, what do we have today to stop it (if at all) ?
atrus 10 hours ago [-]
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 6 hours ago [-]
> 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 7 hours ago [-]
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.
fouronnes3 14 hours ago [-]
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.
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 8 hours ago [-]
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
jcfrei 13 hours ago [-]
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 13 hours ago [-]
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 11 hours ago [-]
>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 11 hours ago [-]
Yeah, not the entire northern sky at least. It's located only 30 degrees south though, so its coverage will be pretty damn good.
carlsborg 14 hours ago [-]
The great filter: light years of travel needed by detection probes.
andrewstuart 13 hours ago [-]
Are we going to be able to get a close look at this?
russdill 7 hours ago [-]
Not really, the sun will be in a rather inconvenient position.
andrewstuart 13 hours ago [-]
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?
hermitcrab 9 hours ago [-]
Objects can get flung out of solar systems when they pass close to large objects. Similar to how spacecraft get gravity assists.
alganet 6 hours ago [-]
> But seriously, why would interstellar objects come towards our solar system?
Why wouldn't they?
coolspot 6 hours ago [-]
Because to go through plane like that they need to match our solar system speed relative to galaxy.
alganet 5 hours ago [-]
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 5 hours ago [-]
Because space is big. Really really big.
alganet 4 hours ago [-]
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.
Jyaif 12 hours ago [-]
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.
tomhow 17 hours ago [-]
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.
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
“Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is.” ~Douglas Adams
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.
https://www.joshworth.com/dev/pixelspace/pixelspace_solarsys...
https://www.youtube.com/watch?v=1AAU_btBN7s
[edit] arrgh. brain spaz forgot to put in the URL
Not if it's at the speed of light, the journey will be instantaneous for the (massless) traveller.
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
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."
[1] https://www.newyorker.com/magazine/2007/02/12/a-tranquil-sta...
"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
"specified object was not found"
What do you mean by 'active' here - has a plume?
C/2025 N1
Edit: does this link work?
https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=C%2F2...
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/
For example, Earth's orbit around the sun is ~0.0167, Pluto's is 0.248.
Terraform Mars!
“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
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.
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.
Which one is more numerous, less prone to natural forcings?
A thick enough atmosphere will stop pretty much all the charged particles from the normal solar radiation.
And clearly even our mag field (and Sun's heliosphere) is not enough to shield us from those crazy cosmic rays.
If we could steer it to hit one of Mars’s poles, it might do a bit of terraforming for us!
Thanks!
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:
1/3rd of the mountain in TNT.Nope, I can't conceive of that much energy.
Or 5-ish Tsar Bomba per country on Earth.
Or 3466 Hiroshima nukes.
Or 17 Hiroshima nukes per country.
…
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.
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
Way too slow, it's more like 70km/s (or 90) - seems you left out a k.
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).
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).
No, I can’t really imagine what that means, either.
I linked an orbit viewer above if you want to look.
I did a full proper n-body integration and it is not visually different than this.
Is this also random chance or is there a reason why it's so close to the plane of the solar system?
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.
[1] https://en.m.wikipedia.org/wiki/Extremely_Large_Telescope
https://upload.wikimedia.org/wikipedia/commons/c/c5/Comparis...
[1] https://www.eso.org/public/announcements/ann25001/
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...
If it is an inactive rock, then we will not see it as any more than a point of light during its visit.
This is one of the big reasons I love HN
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.
https://youtu.be/X3N-DjVXh44
so we are probably gonna notice a lot more of them
"Third cargo chest discovered"
"Maybe they've been sailing by here already for a long time and we just didn't notice."
When ʻOumuamua flew past, we should have noticed it was a passive sensor drone. Now it is too late.
https://en.wikipedia.org/wiki/Local_Bubble
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.
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.
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 ʻOumuamua. It was not made specifically to find interstellar objects transiting the solar system.
In there, one estimate of the number of these objects is
Which (my, probably wrong, calc) implies roughly one inside the orbital volume at the radius of Saturn's orbit at any time.Perhaps Oumuamua was the mothership and the solar system is now swarming with cubesats we're not noticing.
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
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.
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.
Probably only Project Orion would be able to catch up to its current 60kms/s speed by October.
Assuming you don't want to do anything but fly by or smash into it
The entire _southern hemisphere_ night sky right?
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?
Why wouldn't they?
Why should I believe some object was _intentionally_ thrown here? Maybe it is just one of those random rocks.
There's nothing statistically weird about these interstellar objects.
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.
The original URL was https://minorplanetcenter.net/mpec/K25/K25N12.html, which I've included in the header.