Evidence · 3I/ATLAS

Much of the water came from icy grains, not the nucleus

Radio OH and SOHO/SWAN analyses find up to 80 per cent of the water came from an extended source of icy grains in the coma, which adds gas but no push to the nucleus.

Suggestive0

What it means

Key questionWhat pushes 3I/ATLAS off a purely gravitational path?

No answer ahead yet

Openunchanged

Part of itWhich gas carries the push: carbon dioxide, water or carbon monoxide?

2 answers, none ahead yet

Openunchanged

Answer this evidence bears onWater carries the push

Counts againstnone for, 1 against

Still possibleunchanged

What it implies

Water measured in the coma overstates the water pushing the nucleus.For: Which gas carries the push: carbon dioxide, water or carbon monoxide?

Next steps 1

Refit the orbit with CO2 and water activity laws

Could shiftFair odds~30 h

On: Which gas carries the push: carbon dioxide, water or carbon monoxide?

7score

Details

Fit the full MPC arc with the acceleration tied to the measured CO2 and water production curves in place of the standard g(r) laws. Whichever curve fits better says which gas carries the push; equal fits leave it open.

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

Sources 2

Perihelion Asymmetry in the Water Production Rate of the Interstellar Object 3I/ATLAS

Tan et al. 2026

SRC

Pre-perihelion Volatile Evolution of Interstellar Comet 3I/ATLAS Indicating Significant Contribution from Extended Source in the Coma

Li et al. 2026

SRC

Cite it

Mysteries Department. (2026). Much of the water came from icy grains, not the nucleus [Evidence EVD0DFQ4MVJ784S]. https://mysteriesdept.com/r/EVD0DFQ4MVJ784S

@misc{mysteriesdept_evd0dfq4mvj784s,
  title     = {Much of the water came from icy grains, not the nucleus},
  author    = {{Mysteries Department}},
  year      = {2026},
  note      = {Evidence, catalog key EVD0DFQ4MVJ784S},
  url       = {https://mysteriesdept.com/r/EVD0DFQ4MVJ784S}
}