Answer · 3I/ATLAS

A crust made by cosmic rays on the journey

Billions of years of galactic cosmic rays reworked the outer metres of 3I/ATLAS, so the CO2-rich, red coma seen inbound came from a processed crust rather than the pristine interior.

Still possibleAnswers 1 question0

Where it stands

Still possibleTwo pieces of evidence for, none against. It needs two reviews to be accepted.

What it predicts

The coma's composition shifts as the outer metres are lost
Methane and other volatiles appear late, from below the processed layer

What would rule it out

The coma's composition stays the same after more than about 20 m of surface has been removed

Evidence 2 for · none against

CO2-to-water ratio fell from 7.6 to about 0.1

Supported

FOR

Cosmic-ray processing explains the CO2 and the red colour

Suggestive

FOR

The questions it answers

What is 3I/ATLAS made of, and why is its chemistry so unlike a Solar System comet's?

OpenNo answer ahead yet

Cite it

Mysteries Department. (2026). A crust made by cosmic rays on the journey [Answer ANS0DFQ17SXMJ3A]. https://mysteriesdept.com/r/ANS0DFQ17SXMJ3A

@misc{mysteriesdept_ans0dfq17sxmj3a,
  title     = {A crust made by cosmic rays on the journey},
  author    = {{Mysteries Department}},
  year      = {2026},
  note      = {Answer, catalog key ANS0DFQ17SXMJ3A},
  url       = {https://mysteriesdept.com/r/ANS0DFQ17SXMJ3A}
}