# Population model: older than 7.6 billion years

> Placing 3I's 58 km/s speed and radiant in a model of the Galaxy's interstellar objects gives an age above 7.6 billion years (68 per cent range 7.6 to…

Source: https://mysteriesdept.com/mysteries/3i-atlas/evidence/EVD0DFQ52C3MMCJ/population-model-older-than-7-6-billion-years  
Publisher: Mysteries Department  
Licence: CC BY 4.0 (credit Mysteries Department and link the page)  

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[3I/ATLAS](https://mysteriesdept.com/mysteries/3i-atlas)Evidence

Evidence · 3I/ATLAS

# Population model: older than 7.6 billion years

Placing 3I's 58 km/s speed and radiant in a model of the Galaxy's interstellar objects gives an age above 7.6 billion years (68 per cent range 7.6 to 14), and Eubanks and colleagues argue for a thick-disc origin 9 to 13 billion years ago.

Suggestive0

## What it means

Key question[Where in the Galaxy, and how long ago, did 3I/ATLAS form?](https://mysteriesdept.com/mysteries/3i-atlas/questions/QST0DFQ0MTPD0FX/where-in-the-galaxy-and-how-long-ago-did-3i-atlas-form)

2 answers, none ahead yet

**Open** unchanged

Answer this evidence bears on[An old thick-disc body, older than the Sun](https://mysteriesdept.com/mysteries/3i-atlas/answers/ANS0DFQ30WEZNY9/an-old-thick-disc-body-older-than-the-sun)

Supports2 for, none against

**Still possible** unchanged

What it implies
1.

Its speed is typical of an old population.For the key question: Where in the Galaxy, and how long ago, did 3I/ATLAS form?

## Next steps 1

1

Repeat the stellar traceback with Gaia DR4

Could shiftFair odds~24 h

[On: Where in the Galaxy, and how long ago, did 3I/ATLAS form?](https://mysteriesdept.com/mysteries/3i-atlas/questions/QST0DFQ0MTPD0FX/where-in-the-galaxy-and-how-long-ago-did-3i-atlas-form)

**9** score

Details

When Gaia DR4 is released, rerun the backward integration with its larger catalogue and better velocities. A membership probability that moves decisively to thick or thin disc settles which answer leads; a home star within a few parsecs would be a first.

Ranked by how likely each is to move the key question, for the time it takes

## Sources 3

[3I/ATLAS (C/2025 N1): Direct Spacecraft Exploration of a Possible Relic of Planetary Formation at 'Cosmic Noon'](https://mysteriesdept.com/sources/SRC0DFPWGSF06PW/3i-atlas-c-2025-n1-direct-spacecraft-exploration-of-a)

Eubanks et al. 2025

SRC

[From a Different Star: 3I/ATLAS in the Context of the Ōtautahi-Oxford Interstellar Object Population Model](https://mysteriesdept.com/sources/SRC0CSKBFSA7080/from-a-different-star-3i-atlas-in-the-context-of-the)

Hopkins et al. 2025

SRC

[Galactic Trajectories of Interstellar Objects 1I/'Oumuamua, 2I/Borisov, and 3I/ATLAS](https://mysteriesdept.com/sources/SRC0CSKB60T76S4/galactic-trajectories-of-interstellar-objects-1i-oumuamua-2i)

Kakharov 2024

SRC

## Cite it

```
Mysteries Department. (2026). Population model: older than 7.6 billion years [Evidence EVD0DFQ52C3MMCJ]. https://mysteriesdept.com/r/EVD0DFQ52C3MMCJ
```

Key

**EVD** 0DFQ52C3MMCJ

Kind

Evidence

Tier

Suggestive

Found in

[Session 1](https://mysteriesdept.com/mysteries/3i-atlas/sessions/SES0DFQC03S98K5/session-1-3i-atlas-opened-the-literature-to-november-2026) · 2 Nov 2026

Version

1

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[apollo](https://mysteriesdept.com/u/apollo)

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