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Gaia spots stars flying between galaxies
- alex_duf 8y agoI wonder how we'd feel as a species if our star was one of these instead of being the Sun. We'd see this amazing group of stars and planets, going away from us knowing the more we wait for space travel to less likely our species would to reach any other star system.
- madeuptempacct 8y agoThe more interesting question is how you would feel if one of the inbound stars was inbound directly toward our sun.
- comboy 8y agoYou underestimate the emptiness of space.
- wlesieutre 8y agoWe had a "close" flyby (0.82 lightyears) about 70,000 years ago! https://en.wikipedia.org/wiki/Scholz%27s_Star https://en.wikipedia.org/wiki/Scholz%27s_Star
- TeMPOraL 8y ago> A star is expected to pass through the Oort Cloud every 100,000 years or so.[4] An approach as close or closer than 52,000 AU is expected to occur about every 9 million years.[2] In about 1.4 million years, Gliese 710 will pass somewhere between 8,800 and 13,700 AU from the Sun. Just wow.
- njarboe 8y agoMaybe interstellar travel is basically impossible but there might be very long lived civilizations that propagate to others stars when one comes near by. Imagine what happens when both stars are populated by different long lived civilizations and they start to get near each other. I would love to read a good book speculating about such an event.
- planteen 8y agoThat "close" encounter was still over three orders of magnitude further out than Pluto (which has a distance of around 0.000624 ly).
- TeMPOraL 8y agoI have this science fiction writing/game backstory idea I recently came up with. Feel free to use it, as I guess I won't get around to do anything with it any time soon. Copying straight from my "ideas" file: At some point in time (past or future, or magically also present), a star passed in very close vicinity to our sun. It had a habitable planet in its system, full of alien plant and animal life. For the brief moment it was Δv-accessible, it was studied, and eventually colonized. The people going there knew it was going to be a one-way trip, as the star eventually moved further away. Possible stories to set before, during, or after encounter (or even long, long after). (This works for no-FTL, hard sci-fi setting. By "very close vicinity" I mean, close enough for us to reach it via sublight propulsion, but still far enough not to mess up the inner Solar System gravitationally.) -- EDIT: Wow, turns out this isn't even that implausible - https://news.ycombinator.com/item?id=18123098 https://news.ycombinator.com/item?id=18123098.
- kbenson 8y agoWow. Just the changed mindset (compared to the present, at least) would be amazing. "Are there others out there? Yes. And they're like us. We should try to meet again some day." It's almost like a modern day Atlantis myth, but true. If you want a really interesting setting for a game/book, imagine a major regression on Earth (standard post-apocalypse trope), and the colonists finally find a way to visit again...
- soraki_soladead 8y agoWasn't this sort of the idea behind the Homeworld games? Ancient artifact discovered in Antartica, left by the original settlers of Earth, leads to a quest to travel "home".
- TeMPOraL 8y agoSort of. It wasn't Earth, and the artifact was found in a desert.
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- stephengillie 8y agoHow would it impact a solar system if one of these relativistic stars got too close? Any chance it could pick up a few planets, or would they mostly be flung into space? Along that point, what does the heliosphere of such a star look like - a giant comet? Lastly, were a life-bearing planet sent into space this way have any chance of maintaining that life without a parent star to heat and magnetically shield it?
- behringer 8y agoChances are nothing would happen as space is vast, but if it did get too close, it would be going way faster than anything around it, as it would be on a different plane. It would just scanner whatever is nearby like a big boat in a small pond. The heliosphere would look normal because there would be no drag on it. A comet has a tail because the sun is both melting and pushing material away from it. Lastly, we could probably heat our homes with the core of the planet for a little while, but everything would be dead within a few years. I think the Twilight Zone covered this scenario in an episode! In it the Earth started moving away from the sun for no good reason.
- Scramblejams 8y agoThe Milky Way is due to collide with Andromeda in about 4 billion years, and there is apparently a 12% chance that whatever's left of us (!) will be spun out in the process. https://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_collision#Fate_of_the_Solar_System https://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_co...
- Gravityloss 8y ago"of course the galaxies are devoid of life. The amount of supernovas is just too great."
- pavel_lishin 8y agoThere's at least two stories I've read with a similar premise; one was an interesting tale of a planet that stifles its scientific development, and is almost-unaware that they're about to approach another star. Damned if I remember what it's called, or who wrote it, though...
- abecedarius 8y agoPerhaps https://en.wikipedia.org/wiki/The_Collected_Stories_of_Vernor_Vinge#%22The_Science_Fair%22 https://en.wikipedia.org/wiki/The_Collected_Stories_of_Verno...
- pavel_lishin 8y agoThat's it!
- alasdair_stark 8y agoYou should check out the Iain M. Banks novel, Against a Dark Background. It's set outside of his Culture Universe, in a planetary system orbiting an intergalactic star. There is no FTL so humanity is effectively trapped. I wish that Banks had expanded on the idea with further novels as I really enjoyed reading about the cyclical rise and fall of societies while humanity explored different social/political structures, hoping to achieve some form of long-term stability.
- Ush2iaph 8y agoWhat better intergalactic colony ship than a whole star system accelerated to a significant fraction of c.
- aaroninsf 8y agoHad the same thought... it's the Westfalia camper of a Class 2.5 civilization.
- jacquesm 8y agoHope they have invented a better zipper then!
- Flow 8y agoBut how can a civilization even start to move a star to a degree it fills a purpose?
- stcredzero 8y agoShkadov Thrusters https://www.youtube.com/watch?v=_VetAm7fCS0 https://www.youtube.com/watch?v=_VetAm7fCS0
- def_ConGame 8y agoThat guy's channel is awesome, but his Rhotacism drives me up the wall. https://en.wikipedia.org/wiki/Rhotacism_(speech_impediment) https://en.wikipedia.org/wiki/Rhotacism_(speech_impediment)
- stcredzero 8y agoI just imagine Elmer Fudd dressed like Carl Sagan.
- trhway 8y agoBefore the level of moving stars, they definitely can reach the level of being capable to jump onto a suitably identified star moving in the desired direction.
- scentoni 8y agoThat's no star...
- stephengillie 8y ago...It's a pop culture reference.
- MichaelMoser123 8y agoCan these very fast stars bump into another solar system? Probably very unlikely, but is it possible?
- mitchty 8y agoPossible yes, likely, no. An example, the collision of the Milky Way with Andromeda is likely to produce no collisions of solar systems. Space is big.
- MichaelMoser123 8y agoBut if there is a different universe where gravity is not factored by the inverse square of the distance...
- graedus 8y ago> An example, the collision of the Milky Way with Andromeda is likely to produce no collisions of solar systems. I was curious about this, so I found this source[0] via wikipedia: "Although the galaxies will plow into each other, stars inside each galaxy are so far apart that they will not collide with other stars during the encounter. However, the stars will be thrown into different orbits around the new galactic center. Simulations show that our solar system will probably be tossed much farther from the galactic core than it is today." Interpreted literally, it would seem this at least leaves open the idea that a star passing through any other star's solar system and, say, sending its planets into wildly different orbits or flinging some into interstellar space, is meaningfully more likely than a star actually physically hitting another star, but I haven't seen the math. I wouldn't be surprised if they're both extremely unlikely - the diameter of our solar system appears to be about 8500 times larger than the diameter of the sun, which may not change the odds in any significant way. [0] https://www.nasa.gov/mission_pages/hubble/science/milky-way-collide.html https://www.nasa.gov/mission_pages/hubble/science/milky-way-...
- sehugg 8y agoThere used to be a relevant X screensaver ... ah, here's a port of it to JS: https://rtoal.github.io/galaxies/galaxies.html https://rtoal.github.io/galaxies/galaxies.html
- cletus 8y agoIsaac Arhur touches on this subject in one of his videos, Intergalactic Colonization [1]. Basically, the void between galaxies isn't actually that much of a void. It's just in intergalactic space stars tend to be hundreds or thousands of light years apart rather than the 5-10 (where we are in the Milky Way) or, say, in light weeks or less in the galactic center. It's known (and he talks about) stars being ejected from galaxies. This is important because a lot of intergalactic stars have high metallicity and are likely to at least some of the time still have their planetary systems. It is interesting to consider where these stars came from. A nearby galaxy being the obvious candidate. I wonder if the 3D velocity measurements can be precise enough to ever determine this to a high degree of likelihood. It would be cool to find some intergalactic visitors in our own galaxy. [1]: https://www.youtube.com/watch?v=xRB7a89Jh7w https://www.youtube.com/watch?v=xRB7a89Jh7w
- valarauca1 8y agoDealing with dark matter halo's is likely non-trivial. While the science is still out, the most likely dark matter candidate is 15-50 solar mass black holes [1]. The idea of having thousands's of light years of empty space with the same approximate black hole density as the galactic disk, but without the dust, gas, or stars to see their effects is rather a horrifying barrier to exploring the halo stars. [1] This is a possibly theory. It is counter to axion theory (massive weakly interactive particles) as Axions require CPT violations we can't create experimentally, and LIGO is seeing collisions of black holes in the correct mass range, and which can't be created via stellar collapse (as they're just too big). Which lends some credibility to this mass range (also it wouldn't impact the CMB so the theory holds a fair amount of water).
- drjesusphd 8y agoHorrifying in what way? In the sense of being nearly impossible to navigate taking into account their gravitational effects? If these black holes are just as dense as in the galaxy, wouldn't that make navigating the galaxy just as difficult? The distances are longer, but that just means corrective burns have a stronger effect on the future trajectory.
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- jetrink 8y agoThe abstract of the paper says that the two fastest stars are traveling at 700 km/s. For scale, at that speed, a star would take 20 million years to travel from the outer edges of the galaxy to the center. (That ignores any acceleration as the star falls inward, of course.)
- Razengan 8y agoStars outside galaxies, planets without stars, asteroid clusters drifting through nebulas, worlds orbiting black holes.. We are tantalized with so many possibilities to be explored, without being able to go out and touch them. I really wish humanity or at least some nations would focus on direct exploration of the cosmos. It would open up entire new industries, provide more jobs, and more beneficial side effects compared to how much we spend on war and preparing for war. Most importantly perhaps, it could provide a collective sense of hope and purpose that seems to be increasingly missing from our species.
- leovuyk 8y agoSurprise! Gaia satellite sees Stars flying between galaxies. Quantum-FFF Theory suggestion: Due to still undetected Galaxy Anchor Black Hole (GABH) gravity sources. at both sides of the spiral galaxy, in combination with Outer HI disc black hole "slingshots" for acceleration out of the galaxy.see: https://bigbang-entanglement.blogspot.com/2018/10/surprise-gaia-satellite-sees-stars.html https://bigbang-entanglement.blogspot.com/2018/10/surprise-g... see: https://www.sciencedaily.com/releases/2018/10/181002103000.htm https://www.sciencedaily.com/releases/2018/10/181002103000.h... see also for "the origin of dead galaxies": http://vixra.org/pdf/1706.0490v2.pdf http://vixra.org/pdf/1706.0490v2.pdf