[Arizona_928]

When a comet gets close to the sun, solar radiation heats its icy nucleus. Volatile ices, like carbon dioxide, carbon monoxide or water, sublimate directly into gas, carrying away dust and small rocks. Smaller objects have a larger surface area per unit mass, making them more vulnerable to excess heating and further mass loss. This process can cause the comet to break apart if the mix of ice and dust cannot withstand the resulting thermal stress.
The jets of sublimated gas are not distributed evenly across the comet’s surface and act like thrusters, spinning up the nucleus. Fast rotation could also break up the comet as inferred for comet 332P/Ikeya-Murakami, whose rapid spin likely led to its fragmentation (see discussion here). Breakup from gravitational tides was demonstrated in 1994, when the fragments of comet Shoemaker-Levy 9, torn apart by Jupiter’s gravity, crashed into the planet (see discussion here).

https://avi-loeb.medium.com/will-3i-atlas-break-up-45687c4d7542