A comet nicknamed the “golden comet,” C/2025 K1 (ATLAS), has split into three pieces after passing close to the Sun, Italian astronomers report. Images from Nov. 11–12 with the Copernicus Telescope at Asiago show the breakup after the comet passed about 0.33 AU (≈30.7 million miles) from the Sun. The fragmentation, seen nearly in real time, followed the comet’s Oct. 8 perihelion. Scientists attribute such breakups to intense heat, tidal stresses and rapid outgassing near the Sun.
Golden Comet C/2025 K1 (ATLAS) Shatters into Three After Near‑Sun Encounter
A comet nicknamed the “golden comet,” C/2025 K1 (ATLAS), has split into three pieces after passing close to the Sun, Italian astronomers report. Images from Nov. 11–12 with the Copernicus Telescope at Asiago show the breakup after the comet passed about 0.33 AU (≈30.7 million miles) from the Sun. The fragmentation, seen nearly in real time, followed the comet’s Oct. 8 perihelion. Scientists attribute such breakups to intense heat, tidal stresses and rapid outgassing near the Sun.
06:45 AM, 11/15/2025Science
Italian astronomers capture comet C/2025 K1 (ATLAS) breaking apart
Comet C/2025 K1 (ATLAS), nicknamed the “golden comet,” has fragmented into three pieces after a close passage by the Sun, astronomers in Italy report. The breakup was recorded in images taken on Nov. 11–12 with the Copernicus Telescope at the Asiago Observatory in northern Italy.
The comet was first discovered in May 2025 by NASA’s Asteroid Terrestrial-impact Last Alert System (ATLAS), the same global survey that found interstellar visitor 3I/ATLAS. C/2025 K1 reached perihelion (its closest point to the Sun) on Oct. 8, and subsequently was observed to have split into three distinct fragments.
Observations show the object after it passed roughly 0.33 astronomical units (≈30.7 million miles) from the Sun — a distance closer than Mercury’s orbit. Italian observers reported seeing the fragmentation unfold in near real time during the Nov. 11–12 observing session.
During the same night, Francesco Ferrigno of Parthenope University also photographed unusually bright auroras lighting the sky, caused by a severe geomagnetic storm affecting Earth at that time.
Astronomers say comet breakups are common near the Sun. Intense solar heating, tidal stresses and rapid outgassing of trapped ices and gases can cause internal pressure to rise and fracture the comet’s nucleus, producing multiple fragments and extended dust tails.
Why this matters: Fragmentation provides a rare opportunity to study a comet’s internal structure and composition as separate pieces reveal fresh material. Continued monitoring will help determine whether the fragments remain active or disperse over time.