Atlas didn't break up and is still in one piece according to latest observations.
Quote:Images taken of 3I/ATLAS on November 11, 2025 show a single body, with no evidence for breakup following the perihelion passage two weeks earlier. The images, reported here, were taken by David Jewitt and Jane Luu on the Nordic Optical Telescope with a primary mirror of 2.56-meter diameter, located at La Palma in the Canary Islands
Quote:Given the large-scale jets reported recently, the fact that 3I/ATLAS remains a single body is surprising for a natural comet. In particular, the large-scale image of 3I/ATLAS reported here on November 9, 2029 shows jets reaching out to ~1 million kilometers towards the Sun and ~3 million kilometers in the opposite direction, as discussed here. For a natural comet, the outflow velocity of the jets is expected to be 0.4 kilometers per second, of order the sound speed of gas at the distance of 3I/ATLAS from the Sun. At that speed, the jets must have persisted over a timescale of 1–3 months.
Given that the jets towards the Sun were stopped by the solar wind at a distance of a million kilometers, I calculated here that their mass density is a few million proton masses per cubic centimeter at a distance of a million kilometers from 3I/ATLAS. The product of this mass density and the outflow speed, implies a mass flux of 5 billion tons per month per area of a million-kilometer on a side.
https://miro.medium.com/v2/resize:fit:48...QgmWWQ.png