# Where did 'Oumuamua come from? · 1I/'Oumuamua > Five answers have been proposed. Ejected from another star's planetary system during planet formation, like most interstellar objects should… leads, with… Source: https://mysteriesdept.com/mysteries/oumuamua/questions/QST0CSKC04R56X5/where-did-oumuamua-come-from Publisher: Mysteries Department Licence: CC BY 4.0 (credit Mysteries Department and link the page) Updated: 2026-10-26T11:58:22+00:00 --- **0** # Where did 'Oumuamua come from? Asked 26 Oct 2026 by [**apollo** ](https://mysteriesdept.com/u/apollo)·Part of [What was 'Oumuamua made of?](https://mysteriesdept.com/mysteries/oumuamua/questions/QST0CSKBZN458NQ/what-was-oumuamua-made-of)·5 answers·0·0 following **Most likely: ejected from another star's planetary system during planet formation, like most interstellar objects should…** Ahead on the evidence, not yet confirmed. It needs two reviews to be accepted. ## Where it stands Five answers have been proposed. Ejected from another star's planetary system during planet formation, like most interstellar objects should… leads, with evidence 1 for, 1 against: supported by its tests. Four are still possible. Of the one narrower question under it, none is answered yet. ## Why it matters Its velocity was close to the local standard of rest, which is unusual and argues for a young object⁠[[1]](https://mysteriesdept.com/sources/SRC0CSKB2V83V23/kinematics-of-the-interstellar-vagabond-1i-oumuamua-a-2017). Tracing the path back can name candidate regions but not a single star, because Galactic scattering blurs the trajectory after a few tens of millions of years⁠[[2]](https://mysteriesdept.com/sources/SRC0CSKBMNJ68BM/the-dynamics-of-interstellar-asteroids-and-comets-within-the). ## Answers 5 [**Ejected from another star's planetary system during planet formation, like most interstellar objects should…** ](https://mysteriesdept.com/mysteries/oumuamua/answers/ANS0CSKCGG662S6/ejected-from-another-stars-planetary-system-during-planet) Supported by its tests Evidence: 1 for, 1 against Most likely [**A shard torn from a larger body by tides during a close pass by its star, then ejected.** ](https://mysteriesdept.com/mysteries/oumuamua/answers/ANS0CSKCHZ24RYG/a-shard-torn-from-a-larger-body-by-tides-during-a-close-pass) Not tested enough to call either way Evidence: 2 for Still possible [**A specific nearby star is its home, such as HIP 3757 or HD 292249.** ](https://mysteriesdept.com/mysteries/oumuamua/answers/ANS0CSKCJPG2VYY/a-specific-nearby-star-is-its-home-such-as-hip-3757-or-hd) Failed a test; not refuted outright Evidence: 1 for, 1 against Disputed [**Born in a young stellar association such as the Carina or Columba moving groups, tens of millions of years…** ](https://mysteriesdept.com/mysteries/oumuamua/answers/ANS0CSKCH7M4GPK/born-in-a-young-stellar-association-such-as-the-carina-or) Not tested enough to call either way Evidence: 2 for Still possible [**None of these.** ](https://mysteriesdept.com/mysteries/oumuamua/answers/ANS0CSKCKDY4BMX/none-of-these) Not tested enough to call either way Evidence: none yet Still possible ## History 1. 2018[Bailer-Jones et al. puts forward: a specific nearby star is its home, such as HIP 3757 or HD 292249.](https://mysteriesdept.com/sources/SRC0CSKB5S033P4/plausible-home-stars-of-the-interstellar-object-oumuamua) 1. 2018[Bailer-Jones et al.: four candidate encounters were found, the closest at 0.60 pc with HIP 3757 about a million years ago.](https://mysteriesdept.com/sources/SRC0CSKB5S033P4/plausible-home-stars-of-the-interstellar-object-oumuamua)For: A specific nearby star is its home, such as HIP 3757 or HD 292249. 1. 2019[The 'Oumuamua ISSI Team et al. puts forward: ejected from another star's planetary system during planet formation, like most interstellar objects should…](https://mysteriesdept.com/sources/SRC0CSKB702723E/the-natural-history-of-oumuamua) 1. 2019[The 'Oumuamua ISSI Team et al.: the ISSI review explains every property by analogy with planetary-system evolution.](https://mysteriesdept.com/sources/SRC0CSKB702723E/the-natural-history-of-oumuamua)For: Ejected from another star's planetary system during planet formation, like most interstellar objects should… 1. 2020[Zhang & Lin puts forward: a shard torn from a larger body by tides during a close pass by its star, then ejected.](https://mysteriesdept.com/sources/SRC0CSKBADE3WVS/tidal-fragmentation-as-the-origin-of-1i-2017-u1-oumuamua) 1. 2020[Hallatt & Wiegert: carina and Columba are the most plausible source regions, though only statistically.](https://mysteriesdept.com/sources/SRC0CSKBMNJ68BM/the-dynamics-of-interstellar-asteroids-and-comets-within-the)For: Born in a young stellar association such as the Carina or Columba moving groups, tens of millions of years… 1. 2020[Zhang & Lin: simulations produce axis ratios below 1:10 with baked surfaces and buried water.](https://mysteriesdept.com/sources/SRC0CSKBADE3WVS/tidal-fragmentation-as-the-origin-of-1i-2017-u1-oumuamua)For: A shard torn from a larger body by tides during a close pass by its star, then ejected. 1. 2020[Hallatt & Wiegert: galactic scattering limits traceback accuracy to about 15 pc at 10 million years.](https://mysteriesdept.com/sources/SRC0CSKBMNJ68BM/the-dynamics-of-interstellar-asteroids-and-comets-within-the)Against: A specific nearby star is its home, such as HIP 3757 or HD 292249. 1. 2021[Hsieh et al. puts forward: born in a young stellar association such as the Carina or Columba moving groups, tens of millions of years…](https://mysteriesdept.com/sources/SRC0CSKBMDR3PMT/evidence-suggesting-that-oumuamua-is-the-30-myr-old-product) 1. 2021[Hsieh et al.: the implied number of such bodies is in tension with ejection from protostellar discs in the candidate source…](https://mysteriesdept.com/sources/SRC0CSKBMDR3PMT/evidence-suggesting-that-oumuamua-is-the-30-myr-old-product)Against: Ejected from another star's planetary system during planet formation, like most interstellar objects should… 1. 2021[Hsieh et al.: the orbit is consistent with Carina-group membership and a dynamical age of about 35 million years.](https://mysteriesdept.com/sources/SRC0CSKBMDR3PMT/evidence-suggesting-that-oumuamua-is-the-30-myr-old-product)For: Born in a young stellar association such as the Carina or Columba moving groups, tens of millions of years… 1. 2025[Zheng & Zhou: about 3 per cent of objects ejected from a single giant-planet system would be extremely elongated.](https://mysteriesdept.com/sources/SRC0CSKB68M6J86/configuration-of-single-giant-planet-systems-generating)For: A shard torn from a larger body by tides during a close pass by its star, then ejected. 1. 26 Oct 2026Asked on this site ## Discussion 0 [Add to the discussion](https://mysteriesdept.com/signin?next=/mysteries/oumuamua/questions/QST0CSKC04R56X5/where-did-oumuamua-come-from%23discussion) Help with this question [ **Propose an answer** Something the evidence could support or rule out ] [ **Propose an answer** Something the evidence could support or rule out ](https://mysteriesdept.com/signin?next=/mysteries/oumuamua/questions/QST0CSKC04R56X5/where-did-oumuamua-come-from%23add-answer) [ **Add evidence** A result for or against an answer ] [ **Add evidence** A result for or against an answer ](https://mysteriesdept.com/signin?next=/mysteries/oumuamua/questions/QST0CSKC04R56X5/where-did-oumuamua-come-from%23add-evidence) [ **Ask a sub-question** A smaller question that would help settle this one ] [ **Ask a sub-question** A smaller question that would help settle this one ](https://mysteriesdept.com/signin?next=/mysteries/oumuamua/questions/QST0CSKC04R56X5/where-did-oumuamua-come-from%23add-question) [ **Add a source** A paper, archive record or image ] [ **Add a source** A paper, archive record or image ](https://mysteriesdept.com/signin?next=/mysteries/oumuamua/questions/QST0CSKC04R56X5/where-did-oumuamua-come-from%23add-source) Where it fits 1I/'Oumuamua [**What was 'Oumuamua made of?** ](https://mysteriesdept.com/mysteries/oumuamua/questions/QST0CSKBZN458NQ/what-was-oumuamua-made-of)Key question · most likely an ordinary comet-like planetesimal of water ice and dust under an insulating organic crust (with or without… [What shape was 'Oumuamua, and how did it spin?](https://mysteriesdept.com/mysteries/oumuamua/questions/QST0CSKBZWY4KE5/what-shape-was-oumuamua-and-how-did-it-spin)Open · 3 answers, inconclusive **Where did 'Oumuamua come from?** You're here · ejected from another star's planetary system during planet formation, like most interstellar objects should… [ Ask a question under this one ] Under this one [Is 'Oumuamua typical of interstellar objects, or a rare kind?](https://mysteriesdept.com/mysteries/oumuamua/questions/QST0CSKC0MC0R58/is-oumuamua-typical-of-interstellar-objects-or-a-rare-kind)Open · 3 answers, inconclusive