Comet C/2025 K1 (ATLAS) breaks up after close brush with the Sun
Comet C/2025 K1 (ATLAS), discovered earlier this year, has split into at least three pieces after swinging close to the Sun in early October.
The breakup started around November 4, with fragments B and C now drifting apart—C is currently the brightest.
Astronomer catches the breakup in action
Astronomer Gianluca Masi snapped images of the comet's split in mid-November.
On November 11, astronomers at the Asiago Observatory spotted a "double nucleus."
The fragments are still moving away from each other, with piece C now about four arcseconds from the main chunk.
What scientists are learning from the fragments
Spectroscopic analysis shows ATLAS is low on carbon but has strong ammonia signals—much more than seen back in August.
With the comet breaking up, astronomers get a rare peek inside to understand what it's made of.
Still visible as it nears Earth
Even though it's splitting up, ATLAS will make its closest approach to Earth on November 24 and should remain visible—though its brightness might change thanks to all this cosmic drama.