A comet visible from such a place is a small victory
On a Saturday evening in November, residents of Bengaluru paused beneath one of the world's most light-polluted skies to witness Comet Lemmon — a traveler from the outer Solar System glowing an improbable emerald green above the western horizon. Discovered only ten months prior at Arizona's Mount Lemmon Observatory, the comet C/2025 A6 had journeyed inward toward the Sun long enough to brighten into something a city could not entirely swallow. In an age when artificial light has quietly erased the night sky for billions, this fleeting green apparition was a quiet insistence that the cosmos has not finished surprising us.
- A comet bright enough to pierce Bengaluru's dense urban glow appeared Saturday evening, its emerald coma visible to anyone with binoculars and a sliver of clear sky.
- The city's relentless light pollution turned a straightforward celestial sighting into a small act of determination — residents scanning rooftops and open lots for a dark enough patch of horizon.
- Social media surged with photographs of the glowing green coma and faint dust tail, as people raced to document the comet before it sank below the skyline.
- The green hue — produced by fluorescent diatomic carbon molecules energized by solar ultraviolet radiation — exists only in the dense inner coma, making the color itself as fragile and temporary as the viewing window.
- Unpredictable outgassing events driven by solar heat will continue to brighten and dim the comet erratically, meaning those who looked up Saturday may have caught it at its most vivid.
On a Saturday evening in Bengaluru, something rare broke through the city's electric haze: a comet bright enough to see. C/2025 A6 — Comet Lemmon — hung above the western horizon in an unmistakable emerald glow, vivid enough that residents reached for their phones before it could sink below the skyline.
The comet had been discovered just ten months earlier by astronomers at Mount Lemmon Observatory in Arizona, and had been slowly brightening as it approached the Sun. By the time it reached Bengaluru's skies, binoculars were enough — though the city's pervasive light pollution made the effort harder than it deserved to be. Those who persisted were rewarded with photographs showing the luminous coma and a faint trailing dust tail, both shimmering in that unexpected green.
The color is not reflected sunlight. It comes from diatomic carbon molecules in the coma that absorb ultraviolet radiation from the Sun and re-emit it as visible green light — a process so delicate that it vanishes in the comet's tail, where these molecules have already broken apart. Only the dense cloud of gas nearest the nucleus holds enough of them to glow.
What made Saturday's sighting quietly remarkable was the specific improbability of it: a comet seen clearly from one of the world's most light-saturated cities. In the weeks ahead, solar heat will trigger unpredictable outgassing events, brightening the comet in sudden bursts before dimming it again. The window is real but not permanent. Those who looked up on Saturday caught it at a moment when everything aligned — and were reminded, briefly, that the Solar System's outermost reaches still send visitors through the neighborhood where Earth resides.
On Saturday evening, Bengaluru residents looked up to find something that doesn't happen often: a comet bright enough to see from a city choked with electric light. The visitor was C/2025 A6, known as Comet Lemmon, and it hung above the western horizon with an unmistakable green glow—a color so vivid and unexpected that people reached for their phones to capture it before it sank below the skyline.
The comet had been discovered just ten months earlier by astronomers working at Mount Lemmon Observatory in Arizona. Since then, it had been on a slow approach toward the Sun, growing brighter as the solar heat worked on its icy surface. By the time it reached Bengaluru's skies, it was visible to anyone with binoculars and a clear enough patch of sky, though the city's pervasive light pollution made the task harder than it should have been. Still, residents managed. Social media filled with photographs showing the comet's luminous envelope of gas—the coma—and the faint tail of dust trailing behind it, both glowing that distinctive emerald shade.
The green color itself is not what most people expect from a comet. It is not reflected sunlight bouncing off ice and rock. Instead, it comes from molecules of diatomic carbon, a two-atom form of the element, that exist in the comet's coma. When ultraviolet radiation from the Sun strikes these molecules, they fluoresce—they absorb the energy and re-emit it as visible green light. This process is delicate and temporary. The diatomic carbon breaks apart quickly in the harsh environment of space, which is why the tail of the comet lacks the same green tint. Only the coma, the dense cloud of gas closest to the nucleus, holds enough of these molecules to glow.
What made the sighting remarkable was not just the rarity of seeing a comet at all from a major city, but the specific challenge of doing so from Bengaluru. The city's bright lights—streetlamps, buildings, vehicles, the ambient glow of millions of people living close together—ordinarily wash out all but the brightest celestial objects. A comet visible from such a place is a small victory for anyone who bothers to look up. The intensity of Comet Lemmon's appearance would fluctuate in the coming weeks as solar heat triggered outgassing events, sudden eruptions of gas and dust from the comet's surface that would brighten it unpredictably. This meant the window to see it clearly was not infinite. Those who had managed to spot it on Saturday had caught it at a moment when the conditions aligned: the comet bright enough, the sky dark enough, and the outgassing active enough to make the green glow unmistakable.
For Bengaluru residents who took the time to look, the comet offered a rare reminder that the Solar System extends far beyond the familiar planets, and that visitors from its outer reaches still pass through the inner orbits where Earth resides. The comet would remain visible to Northern Hemisphere observers with binoculars for weeks to come, though its brightness would continue to shift as it drew closer to the Sun. Those who had already seen it knew they had witnessed something that most city dwellers never get to experience.
Notable Quotes
I'm so glad that I witnessed Comet today in the sky— Bengaluru resident on social media
The Hearth Conversation Another angle on the story
What made this comet visible from Bengaluru when so many cities can't see anything at all?
The comet was simply bright enough. It had been approaching the Sun for months, growing more luminous as solar heat worked on it. And the green color—that diatomic carbon fluorescence—made it stand out even against light pollution. But it was still a narrow window.
Why is the tail not green if the coma is?
The molecules that produce the green glow break apart quickly in space. The tail is mostly dust and older gas that has already lost those carbon molecules. Only near the nucleus, in the dense coma, do enough of them survive to fluoresce.
How long will people have to see it?
That's uncertain. The brightness fluctuates as the comet outgasses—sudden eruptions from its surface. Some nights it might be easier to spot, others harder. The window is open now, but it won't stay open forever.
Does this happen often?
Comets visible to the naked eye or binoculars from a city like Bengaluru? No. Most are too faint, or they appear when the sky conditions aren't right. This one aligned—discovery, timing, brightness, and the fact that people were paying attention.
What does it mean that it was discovered in Arizona?
Mount Lemmon Observatory has the equipment and the observers watching for these things. Most comets are found by dedicated astronomers, not by accident. This one was catalogued, tracked, and then people could predict when and where to look for it.