Comet K1/ATLAS: A cosmic runaway that should have burned up near the Sun, but instead shone gold

Triumph over stellar death: how a comet changed color, survived the heat and became a symbol of hope for astronomers

© Dan Bartlett

An incredible drama unfolded in the starry sky: comet C/2025 K1 (ATLAS), which astronomers had already forgiven, survived an encounter with the Sun, did not disintegrate, but exploded with a rare golden glow. This astronomical miracle gave rise to a new scientific fascination and became a sensation among professionals and amateurs of space photography¹. Previously, it was believed that the comet would disintegrate at perihelion, the moment of closest approach to the Sun. But today it eclipses the classic “green guests” and amazes even experienced researchers.

Encounter with the Sun: why was everyone waiting for its end?

On October 8, the comet approached the Sun at a distance of only 49 million kilometers.². For icy bodies, this is a near-fatal challenge — the powerful gravitational and thermal stress often tears apart the nucleus, turning the comet into a cloud of dust. Years ago, a similar object, ISON, literally dissolved after such a “kiss” with a star. C/2025 K1 was to repeat this fate, but survived and became even brighter.

The brightness increased to 9th magnitude - it could be seen even through amateur telescopes and binoculars.¹The color change itself was captured by astronomer and photographer Dan Bartlett, who won the Astronomy Photographer of the Year competition.

Comet evolution: unexpected chemical and physical processes revealed

The comet didn't just survive - it changed. Instead of its traditional green or blue color, its tail began to glow gold, even taking on a reddish-brown hue.³. In astronomy, this is a rare phenomenon: the standard “color of life” of a comet depends on molecules evaporating from the nucleus, — C₂ (diatomic carbon), ammonia, cyanide. In K1/ATLAS, the lack of carbon molecules, as spectral studies have shown, made the golden color possible.

Analyses from the Lowell Observatory in Arizona have confirmed that only two comets in the entire history of observations have had such a low amount of carbon compounds. At the same time, some scientists suggest: an extrasolar origin (probably the comet came from another star system), and a unique gas mixture allowed the core to withstand lethal temperatures.

Tail, Dust, and the Golden Effect: The Science of Cometary Transformation

The golden glow is due to the extremely high dust content in the coma (the shell around the nucleus), which reflects sunlight in the “warm” spectral ranges. The comet emits three times more dust than its counterparts — this is confirmed by data from NASA radio telescopes⁴In addition, the low level of gas (water, CO) leads to the absence of green and blue highlights, so a predominantly yellow-red spectrum remains.

The photo clearly shows the shape and structure of the tail: at first it was short and “fluffy,” but after perihelion it lengthened and became almost a “golden ribbon” crossing the night sky.

Two ATLASes — interstellar and “domestic”: differences and parallels

At the same time, another comet, 3I/ATLAS, is near the Sun, and it also changed color (to blue-violet), which has sparked a new wave of research into the origin and composition of these objects' material.⁵Both comets were discovered using ATLAS, an international asteroid threat program that includes observatories in Hawaii, Chile, and South Africa.

Scientists even suggest that the unique composition of the ATLAS comets is due to the fact that they spent millions of years in different environments and were subjected to different cosmic ray bombardments. This is what probably “prepared” K1/ATLAS for the harsh tests near the Sun.

When and how to see the golden comet: advice from astronomers

The comet will be closest to Earth on November 25th⁶It can be seen in the early morning sky, before dawn, especially in the Northern Hemisphere. Astronomers recommend using small telescopes or binoculars, but on the darkest nights the comet is visible even to the naked eye.

The golden glow is the result of sunlight reflecting off fine dust in the tail. Photographers recommend shooting with a long exposure to maximize the colors, even in urban locations.

A symbol of cosmic stability: what does the discovery mean for science and man?

The K1/ATLAS phenomenon has become a scientific sensation — its survival and color change give astronomers a chance to study the processes of transformation of icy bodies near a star, calculate new models for predicting the evolution of comets. It also opens up new prospects for the search for extrasolar objects in the Solar System.

For humans, this story is a reminder of the power of cosmic life: even that which “should have disappeared” can come to life in the fight against the elements. The K1/ATLAS golden trail has become a metaphor for hope in a world where survival often depends on unique properties invisible to the eye.

Sources

1. ZN.ua: Comet began to glow golden after meeting with the Sun
2. Economic Times: ATLAS Comet showed golden glow after Sun approach
3. Live Science: There's another comet ATLAS in our solar system, and it just turned gold after a perilous dance with the sun
4. IFLScience: Golden Comet C/2025 K1 (ATLAS) Is A Chemical Rarity
5. Naked Science: Interstellar comet 3I/ATLAS suddenly flares up before encountering the Sun
6. Newsweek: Astronomers Tracking Rare Golden Comet—How To See From Your Backyard