# A 3D model of the SWAN data peaks near 4 × 10^28

> Re-analysing the SOHO/SWAN hydrogen coma with a three-dimensional Monte Carlo model gives a post-perihelion peak of about 4 × 10^28 molecules a second…

Source: https://mysteriesdept.com/mysteries/3i-atlas/evidence/EVD0DFQ55AT4QTE/a-3d-model-of-the-swan-data-peaks-near-4-10-28  
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

# A 3D model of the SWAN data peaks near 4 × 10^28

Re-analysing the SOHO/SWAN hydrogen coma with a three-dimensional Monte Carlo model gives a post-perihelion peak of about 4 × 10^28 molecules a second, with no outbursts and much of the water from icy grains.

Supported0

## What it means

Key question[Why did 3I/ATLAS's activity and chemistry change so much across perihelion?](https://mysteriesdept.com/mysteries/3i-atlas/questions/QST0DFQ0NWRSHDV/why-did-3i-atlass-activity-and-chemistry-change-so-much)

No answer ahead yet

**Open** unchanged

Part of it[How much water did 3I/ATLAS release at its peak after perihelion?](https://mysteriesdept.com/mysteries/3i-atlas/questions/QST0DFQ0T8NXG7Q/how-much-water-did-3i-atlas-release-at-its-peak-after)

2 answers, none ahead yet

**Open** unchanged

Answer this evidence bears on[Four to eight times 10^28 molecules a second](https://mysteriesdept.com/mysteries/3i-atlas/answers/ANS0DFQ34QCZRCE/four-to-eight-times-10-28-molecules-a-second)

Supports2 for, none against

**Still possible** unchanged

What it implies
1.

The same instrument as the high value, analysed differently, gives the low value.For: How much water did 3I/ATLAS release at its peak after perihelion?

## Next steps 1

1

Run both SWAN models on the same frames

Could decidePoor odds~60 h

[On: How much water did 3I/ATLAS release at its peak after perihelion?](https://mysteriesdept.com/mysteries/3i-atlas/questions/QST0DFQ0T8NXG7Q/how-much-water-did-3i-atlas-release-at-its-peak-after)

**2** score

Details

Apply the Combi and Tan hydrogen-coma models to the same SOHO/SWAN images for 6 November 2025. Agreement near 4 × 10^28 rules out the high value; agreement near 3 × 10^29 rules out the low one. Needs the SWAN team's processed frames.

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

## Sources 1

[Perihelion Asymmetry in the Water Production Rate of the Interstellar Object 3I/ATLAS](https://mysteriesdept.com/sources/SRC0DFPWGSFJKVY/perihelion-asymmetry-in-the-water-production-rate-of-the)

Tan et al. 2026

SRC

## Cite it

```
Mysteries Department. (2026). A 3D model of the SWAN data peaks near 4 × 10^28 [Evidence EVD0DFQ55AT4QTE]. https://mysteriesdept.com/r/EVD0DFQ55AT4QTE
```

Key

**EVD** 0DFQ55AT4QTE

Kind

Evidence

Tier

Supported

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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