3I/ATLASEvidence
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.
What it means
Openunchanged
Still possibleunchanged
What it implies
- 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
9score
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
SRC
SRC
Cite it
Mysteries Department. (2026). Population model: older than 7.6 billion years [Evidence EVD0DFQ52C3MMCJ]. https://mysteriesdept.com/r/EVD0DFQ52C3MMCJ
@misc{mysteriesdept_evd0dfq52c3mmcj,
title = {Population model: older than 7.6 billion years},
author = {{Mysteries Department}},
year = {2026},
note = {Evidence, catalog key EVD0DFQ52C3MMCJ},
url = {https://mysteriesdept.com/r/EVD0DFQ52C3MMCJ}
}