# Third interstellar body discovered in our solar system **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [July 4, 2025, 5:26am UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471 "2025-07-04T05:26:13Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 5, 2025, 2:57pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/21 "2025-07-05T14:57:29Z")
Well, probably the origin of most of them. But I’m not confident enough to say anything as absolute as “all”. Some probably also formed on their own, already isolated from stars. ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [July 5, 2025, 5:51pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/22 "2025-07-05T17:51:43Z")
> [@Chronos](#): > > Some probably also formed on their own, already isolated from stars. Could you elaborate? You mean like deep spaces partulates coming together via gravity? ---
**Author:** ![Johanna](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johanna/32/8318_2.png) [@Johanna](https://boards.straightdope.com/u/Johanna)\ **Post date:** [July 5, 2025, 9:47pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/23 "2025-07-05T21:47:43Z")
I’d like to know if they could trace back its pre-Sol trajectory. Which direction is it coming from? Hercules (being the solar apex)? I’d look for massive stars in our neighborhood that could have yo-yoed it our way. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 6, 2025, 1:33am UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/24 "2025-07-06T01:33:08Z")
> [@Lucas\_Jackson](#): > > Could you elaborate? You mean like deep spaces partulates coming together via gravity? Yes. Basically, the same process that forms stars, just on a smaller scale. Is there a lower limit beyond which that doesn’t work? Maybe. But we don’t know what it is, so maybe objects this small can form on their own. > [@Johanna](#): > > I’d like to know if they could trace back its pre-Sol trajectory. They certainly can with enough data, and if they know it’s interstellar, they probably do have enough data, or close to it, and will know enough soon. But I don’t know what the answer to that is. ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [July 7, 2025, 4:00pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/25 "2025-07-07T16:00:51Z")
> [@Chronos](#): > > Yes. Basically, the same process that forms stars, just on a smaller scale. Interesting. My understanding is that comets are primarily ice. So doing a little googling, I find… _“Water, or H2O, is found throughout the universe and its origins trace back to the earliest moments after the Big Bang and within stars. Hydrogen, a key component of water, was created in the Big Bang, while oxygen is formed in the cores of massive stars. These elements combine to form water molecules in various locations, including interstellar space”_ And… _"Water molecules form in the vast, cold expanses of interstellar space through chemical reactions between hydrogen molecules and oxygen-bearing molecules like carbon monoxide_." So throw in a little gravity and I could see how a comet could self-form. What I don’t understand is how it gets it velocity of 134,000 miles per hour. Or are we passing it at 134,000 miles per hour? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 7, 2025, 4:10pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/26 "2025-07-07T16:10:52Z")
Speeds of everything orbiting the center of the Galaxy are all high. They’re also mostly in similar orbits… mostly, which keeps the relative velocity down somewhat (you’re not likely to get head-on collisions, say)… but it doesn’t take too much difference in orbits to get some pretty impressive orbital speeds. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [July 7, 2025, 4:38pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/27 "2025-07-07T16:38:29Z")
> [@Lucas\_Jackson](#): > > What I don’t understand is how it gets it velocity of 134,000 miles per hour. Or are we passing it at 134,000 miles per hour? You’re thinking too much in Earth terms, instead of space terms. Velocity is relative, so there’s no difference in those two “scenarios”. Now the object did/will gain some speed relative to the sun as it falls into the solar system, but it’ll lose that speed as it leaves. It will change direction, though. ETA: note that objects orbiting the galaxy have typical relative velocities of 10s of km/s. Whatever that translates to in mph. I don’t know, I’m so used to km/s velocities for astronomical situations; mph for those are just huge numbers that don’t mean much to me. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [July 7, 2025, 5:05pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/28 "2025-07-07T17:05:02Z")
I look forward to the woo erupting online. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [July 7, 2025, 5:13pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/29 "2025-07-07T17:13:53Z")
> [@Chefguy](#): > > I look forward to the woo erupting online Was there a lot of woo when Interstellar Object 2 (2I/Borisov) came along? I don’t remember such, but perhaps it didn’t make much spash in the general news. There was some for 'Oumuamua, because Avi Loeb claimed it was likely a spaceship or part of one, mostly because it was an unusual object. Borisov was a garden variety comet. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [July 7, 2025, 5:17pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/30 "2025-07-07T17:17:00Z")
> [@dtilque](#): > > Was there a lot of woo when Interstellar Object 2 (2I/Borisov) came along? Isn’t there always, from some quarter or another? Doomsayers, mostly, I’m guessing. Or just people looking for attention. ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [July 7, 2025, 5:20pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/31 "2025-07-07T17:20:40Z")
> [@dtilque](#): > > There was some for 'Oumuamua, because Avi Loeb claimed it was likely a spaceship I heard an interview with him fairly recently, he is still pushing that. > [@Chefguy](#): > > Isn’t there always, from some quarter or another? What!? Nuttery on the internet? That’s crazy talk, man! ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [July 7, 2025, 5:30pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/32 "2025-07-07T17:30:40Z")
> [@dtilque](#): > > Now the object did/will gain some speed relative to the sun as it falls into the solar system, but it’ll lose that speed as it leaves. It will change direction, though. Could comets or asteroids from another solar system (or from deep space) get trapped into orbiting around our sun? Or do they usually just pass on by? ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [July 7, 2025, 5:44pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/33 "2025-07-07T17:44:26Z")
> [@Lucas\_Jackson](#): > > Could comets or asteroids from another solar system (or from deep space) get trapped into orbiting around our sun? Or do they usually just pass on by? The vast majority will just pass by. In order to be captured into solar orbit, an interstellar object would have to lose a humongous amount of velocity. Which means some other object, such as a planet, would have to take that velocity. A very close approach to Jupiter _might_ do it, but most likely would just redirect the object to some other trajectory that will still just pass by. Maybe if it made a pass through the outer part of Jupiter’s atmosphere it’d lose enough velocity. ---
**Author:** ![CoolHandCox](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/coolhandcox/32/16233_2.png) [@CoolHandCox](https://boards.straightdope.com/u/CoolHandCox)\ **Post date:** [July 7, 2025, 6:24pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/34 "2025-07-07T18:24:55Z")
I’m kind of hung up on how they will be able to tell where it originated. From what I’ve read, this will pass straight through our solar system. And that seems pretty normal. So, for example, let’s say it keeps going and encounters another solar system. That next solar system break out the telescopes and math and that tells them it came from _our_ solar system. How can someone then know if our solar system is where it originated from versus just passed through and originated from a solar system prior to ours…and on and on. Can the math figure that out? It probably can, but it seems complicated and I just don’t understand how. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 7, 2025, 9:38pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/35 "2025-07-07T21:38:37Z")
> [@Lucas\_Jackson](#): > > Could comets or asteroids from another solar system (or from deep space) get trapped into orbiting around our sun? Or do they usually just pass on by? In this particular case, no, not without a collision (I would count an aerobraking pass through a gas giant as a collision): It’s just going too fast. But for a somewhat slower interstellar object, it’s theoretically possible, just unlikely. > [@CoolHandCox](#): > > I’m kind of hung up on how they will be able to tell where it originated. If you take “originated” literally, then we can’t know that. But we can tell where it was before entering our neighborhood. And if the path traces back to some other star system, it’s overwhelmingly likely that that’s the origin, since it’s rare enough for a deep-space object to pass by one star system, and overwhelmingly unlikely for two or more. ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [July 7, 2025, 10:19pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/36 "2025-07-07T22:19:06Z")
> [@Chronos](#): > > since it’s rare enough for a deep-space object to pass by one star system, and overwhelmingly unlikely for two or more. One of the most mind-blowing ‘facts’ I’ve heard is that our galaxy and the Andromeda galaxy are on a collision course with each other. It’s not a head-on smash, but rather a merging of the two galaxies. They will pass through each other, interacting gravitationally, and eventually merging into a single, larger galaxy. But here’s the mind-blowing part; despite our galaxy having up to 400 **b** illion stars and the Andromeda galaxy having one **t** rillion stars, the vast distances between stars mean that individual stars are unlikely to collide during the merger! That’s almost hard to fathom. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [July 7, 2025, 10:24pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/37 "2025-07-07T22:24:27Z")
> [@Lucas\_Jackson](#): > > But here’s the mind-blowing part; despite our galaxy having up to 400 **b** illion stars and the Andromeda galaxy having one **t** rillion stars, the vast distances between stars mean that individual stars are unlikely to collide during the merger! That’s almost hard to fathom. Right. What will collide will be the clouds of gas and dust, since those are multiple light years across. Those collisions will cause the clouds to collapse and there’ll be a burst of star formation. After everything settles down, the result will be an elliptical galaxy (someone has already named it: Milkdromeda) that has little left over gas for new star formation. ---
**Author:** ![Johanna](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johanna/32/8318_2.png) [@Johanna](https://boards.straightdope.com/u/Johanna)\ **Post date:** [July 8, 2025, 12:37am UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/38 "2025-07-08T00:37:27Z")
> [@dtilque](#): > > Avi Loeb claimed it was likely a spaceship We need to have a _Rendezvous with Rama_ mission set up and ready to go at a moment’s notice. Not get caught unawares again. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 8, 2025, 1:29pm UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/39 "2025-07-08T13:29:46Z")
Not so mind-boggling, really. Go outside on a clear night and look up. Yeah, there are a lot of stars out there, but there’s a heck of a lot more non-star space in between them. Even if you put twice that many stars on the same amount of sky, it’s exceedingly unlikely that you’d end up with two stars on top of each other. ---
**Author:** ![Fiendish\_Astronaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fiendish_astronaut/32/3295_2.png) [@Fiendish\_Astronaut](https://boards.straightdope.com/u/Fiendish_Astronaut)\ **Post date:** [July 11, 2025, 10:01am UTC](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471/40 "2025-07-11T10:01:50Z")
So it could be a comet. Not just any comet but a seven billion year old comet. I’m just wondering if we’re going to get a spectacular tail since it might have a lot of material that is ripe to burn. Or perhaps it’s going too fast for that. > **[3I/Atlas: Mystery interstellar object could be the oldest known comet](https://www.bbc.co.uk/news/articles/cx23g5jpj9go)** > > Scientists have been racing to discover the origins of 3I/Atlas since it was spotted last week. [Previous page](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471.md?page=1) [Next page](https://boards.straightdope.com/t/third-interstellar-body-discovered-in-our-solar-system/1020471.md?page=3)