Answer · 3I/ATLAS
About a kilometre across, or a little more
The nucleus of 3I/ATLAS has a radius between roughly 0.4 and 1.7 km.
Where it stands
Still possibleTwo pieces of evidence for, none against. It needs two reviews to be accepted.
What it predicts
- Late Hubble photometry far from the Sun, with little coma, gives a radius under 2 km
- Mass-loss and acceleration balance stays consistent with that size whichever gas drives it
What would rule it out
- A clean nucleus measurement above 1.8 km in radius
Evidence 2 for · none against
FOR
FOR
The questions it answers
Open2 answers, none ahead
Cite it
Mysteries Department. (2026). About a kilometre across, or a little more [Answer ANS0DFQ1MV3GTQV]. https://mysteriesdept.com/r/ANS0DFQ1MV3GTQV
@misc{mysteriesdept_ans0dfq1mv3gtqv,
title = {About a kilometre across, or a little more},
author = {{Mysteries Department}},
year = {2026},
note = {Answer, catalog key ANS0DFQ1MV3GTQV},
url = {https://mysteriesdept.com/r/ANS0DFQ1MV3GTQV}
}