# Kinematic age of 3 to 11 billion years

> Taylor and Seligman's kinematic age for 3I is about 3 to 11 billion years, with a 12 per cent chance its host had [Fe/H] at or below -0.4; a composition…

Source: https://mysteriesdept.com/mysteries/3i-atlas/evidence/EVD0DFQ53AZ1YT9/kinematic-age-of-3-to-11-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

# Kinematic age of 3 to 11 billion years

Taylor and Seligman's kinematic age for 3I is about 3 to 11 billion years, with a 12 per cent chance its host had [Fe/H] at or below -0.4; a composition clock gives only a lower limit of 0.6 billion years.

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[A thin-disc body a few billion years old](https://mysteriesdept.com/mysteries/3i-atlas/answers/ANS0DFQ335PRDVB/a-thin-disc-body-a-few-billion-years-old)

Supports2 for, none against

**Still possible** unchanged

What it implies
1.

Leaves room for an object younger than the Sun.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 2

[Measuring the Age and Initial Composition of Interstellar Objects](https://mysteriesdept.com/sources/SRC0DFPWGSG12RJ/measuring-the-age-and-initial-composition-of-interstellar)

Barry-Taylor 2026

SRC

[The Kinematic Age of 3I/ATLAS and its Implications for Early Planet Formation](https://mysteriesdept.com/sources/SRC0DFPWGSEZJCR/the-kinematic-age-of-3i-atlas-and-its-implications-for-early)

Taylor 2025

SRC

## Cite it

```
Mysteries Department. (2026). Kinematic age of 3 to 11 billion years [Evidence EVD0DFQ53AZ1YT9]. https://mysteriesdept.com/r/EVD0DFQ53AZ1YT9
```

Key

**EVD** 0DFQ53AZ1YT9

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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