# Water took over near perihelion; the ice band vanished

> ESPRESSO spectra show the coma becoming water-dominated near perihelion, and SPHEREx in December 2025 found water emission forty times brighter and the…

Source: https://mysteriesdept.com/mysteries/3i-atlas/evidence/EVD0DFQ54QY5WR5/water-took-over-near-perihelion-the-ice-band-vanished  
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

# Water took over near perihelion; the ice band vanished

ESPRESSO spectra show the coma becoming water-dominated near perihelion, and SPHEREx in December 2025 found water emission forty times brighter and the water-ice absorption mostly gone.

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

Answer this evidence bears on[Heat reached deeper, water-richer layers and icy grains](https://mysteriesdept.com/mysteries/3i-atlas/answers/ANS0DFQ349ZM4Y8/heat-reached-deeper-water-richer-layers-and-icy-grains)

Supports2 for, none against

**Still possible** unchanged

What it implies
1.

Heating released water that was locked away inbound.For the key question: Why did 3I/ATLAS's activity and chemistry change so much across perihelion?

## Sources 2

[SPHEREx Re-Observation of Interstellar Object 3I/ATLAS in December 2025](https://mysteriesdept.com/sources/SRC0DFPWGSFNBN2/spherex-re-observation-of-interstellar-object-3i-atlas-in)

Lisse et al. 2026

SRC

[Very Large Telescope observations of interstellar comet 3I/ATLAS III: High-resolution monitoring of CN and forbidden oxygen emission across the perihelion passage with ESPRESSO](https://mysteriesdept.com/sources/SRC0DFPWGSFX851/very-large-telescope-observations-of-interstellar-comet-3i)

Luco et al. 2026

SRC

## Cite it

```
Mysteries Department. (2026). Water took over near perihelion; the ice band vanished [Evidence EVD0DFQ54QY5WR5]. https://mysteriesdept.com/r/EVD0DFQ54QY5WR5
```

Key

**EVD** 0DFQ54QY5WR5

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

Added by

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

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