Comets in the Night Sky November–December 2025: How to See Lemmon, ATLAS and Interstellar Visitor 3I/ATLAS Tonight (24 November)

Updated: 24 November 2025

On this late November night, the sky is crowded with icy visitors. A bright green comet, a shattered golden comet, a new long‑period “Swan,” and a rare interstellar comet are all sharing the stage — and today, 24 November 2025, they’re also making headlines.

NASA has just released close‑up images of interstellar comet 3I/ATLAS from spacecraft orbiting Mars, while astronomers continue to track the evolving fragments of C/2025 K1 (ATLAS) and the still‑naked‑eye C/2025 A6 (Lemmon). ^[1]

Below is your practical, observer‑friendly guide to which comets you can actually see in the sky in late November and through December 2025, plus a rundown of today’s biggest comet news and how to separate science from hype.

Tonight at a Glance (24 November 2025)

Exact visibility depends on your latitude and local conditions, but for mid‑northern latitudes (roughly 30–55° N), here’s the rough landscape:

Easiest naked‑eye comet
- C/2025 A6 (Lemmon) – about magnitude 5.2, low in the south‑south‑west after sunset in Ophiuchus. Best with binoculars in bright evening twilight. ^[2]
Best telescopic showpieces
- C/2025 K1 (ATLAS) – the “golden” comet, now around magnitude 10–11, high in the northern sky before dawn, in Ursa Major and effectively circumpolar for much of the northern hemisphere. It has broken into multiple pieces, but remains observable in small to medium telescopes. ^[3]
- C/2025 R2 (SWAN) – about magnitude 10–11, in the evening sky around Pisces/Aquarius, well placed after dusk for binoculars or small scopes under dark skies. ^[4]
Scientifically hottest target
- 3I/ATLAS (C/2025 N1) – an interstellar comet around magnitude ~10 in the pre‑dawn sky in Virgo, a couple of degrees above the star Porrima. You’ll need at least large binoculars or, better, a telescope. ^[5]
Fainter, advanced‑observer targets
- C/2024 E1 (Wierzchos) – around magnitude 11–12 in Ophiuchus, still rather close to the Sun (low elongation), making it a challenge in twilight even for experienced observers. ^[6]
- 24P/Schaumasse – a periodic comet slowly brightening but still around magnitude 12–13, best for larger amateur telescopes; it will peak around magnitude 8–9 in early 2026. ^[7]

Now let’s break down each major comet and what’s new about it today.

C/2025 A6 (Lemmon): The Green Comet Still Hanging On in Twilight

If you only go after one comet this week, C/2025 A6 (Lemmon) is your best bet.

How bright is comet Lemmon right now?

TheSkyLive reports an observed magnitude of 5.2, with a coma about 3 arcminutes across and a tail roughly half a degree long, based on observations on 21 November 2025. ^[8]
As of 12 November, its Wikipedia entry notes it was about magnitude 5 and visible to the naked eye and in binoculars, though less than 20° from the Sun, making it a twilight object. ^[9]

In practice, that means Lemmon is technically bright enough to see with the unaided eye under dark conditions, but low altitude and bright evening sky will probably force most people to use binoculars.

Where and when to look

Constellation: Ophiuchus. ^[10]
For mid‑northern latitudes (example: UK, northern US, central Europe):
- Above the horizon from late morning through afternoon.
- Sits low in the south‑south‑west after sunset, setting not long after the Sun (for Greenwich, roughly an hour after). ^[11]
Practical strategy:
- Find a location with an unobstructed south‑west horizon.
- Start sweeping with 7×50 or 10×50 binoculars about 30–45 minutes after sunset.
- Look for a soft, slightly greenish fuzz rather than a sharp “star.”

A popular explainer from People called Lemmon a “rare green comet” visible from mid‑October through early November, peaking around its 21 October closest‑approach. ^[12] Even though we’re now in late November and it’s sliding deeper into twilight, it’s still bright enough to reward persistent observers.

C/2025 K1 (ATLAS): The Golden Comet That Shattered

C/2025 K1 (ATLAS) has had one of the most dramatic arcs of any comet this year.

From survival to breakup

On 8 October 2025, K1 skimmed the Sun at about 0.33 AU, unusually close for a dynamically new comet. It famously turned golden, likely due to an unusual composition lacking some of the carbon‑bearing molecules that give many comets a green glow. ^[13]
Just as astronomers started celebrating its survival, high‑resolution images taken on the night of 11–12 Novembershowed that the nucleus had fractured into multiple pieces. IFLScience reported that “the comet has now broken apart,” with at least two bright fragments visible in professional images. ^[14]

Despite the breakup, the pieces of K1 remain observable.

Where K1 is tonight

TheSkyLive’s ephemeris shows for 24 November 2025 (example: Greenwich location): ^[15]

Constellation: Ursa Major (near the far northern sky).
Magnitude: Predicted around 10.9, with recent observations around magnitude ~10.1 on 23 November.
Distance from Earth: About 0.40 AU, essentially at its closest approach (exact minimum distance is calculated as 0.4033 AU on 25 November). ^[16]
Circumpolar for much of the northern hemisphere, transiting very high (near 80° altitude) before dawn.

A December sky guide from Astronomy Edinburgh notes that by next month, C/2025 K1 has broken up but remains circumpolar and visible all night from high northern latitudes, though continuing to fade. ^[17]

How to observe it

You’ll need at least a small telescope (e.g., 80–100 mm refractor or a 6–8″ Dobsonian).
Because it’s circumpolar in the north, you can:
- Check it in the early morning hours now, when it’s highest.
- Continue following it into December, when moonless windows will help compensate for its fading brightness. ^[18]

Look for an irregular, elongated glow rather than a compact nucleus — a hint at its shattered state.

3I/ATLAS: Interstellar Visitor, New Mars Images and Today’s Hype

What 3I/ATLAS actually is

3I/ATLAS (also designated C/2025 N1) is only the third interstellar object ever confirmed passing through our Solar System, after 1I/ʻOumuamua and 2I/Borisov. It was discovered on 1 July 2025 by the ATLAS survey in Chile. ^[19]

Its orbit is hyperbolic: it’s not gravitationally bound to the Sun and will eventually head back into interstellar space. ^[20]

How bright and where tonight?

The latest observing notes compiled on Wikipedia and ephemeris tools report that: ^[21]

As of 23 November 2025, 3I/ATLAS is around magnitude 10–11, just on the edge of what very large binoculars can show but comfortably in reach of small telescopes.
It sits about 2° above the star Porrima (Gamma Virginis) in Virgo, visible just before sunrise.
Through December it will move from Virgo into Leo and fade beyond magnitude 12, even as it reaches its closest approach to Earth of about 1.8 AU on 19 December 2025 — still far beyond any impact concern. ^[22]

Today’s big science news: Mars spacecraft images

In the early hours of 24 November, Universe Today reported that NASA has finally released a set of close‑up images of 3I/ATLAS from Mars orbit and the Perseverance rover. ^[23]

Key points from those results:

Mars Reconnaissance Orbiter (HiRISE) and MAVEN imaged the comet as it passed just 30 million km from Mars in early October — one of the closest look any NASA spacecraft will get. ^[24]
The images show a coma roughly 1,500 km across, and ultraviolet data from MAVEN reveal details about the gas cloud (including water‑related hydrogen) around the comet. ^[25]
Perseverance even managed a faint detection from the Martian surface, capturing 3I/ATLAS as a subtle smudge against the starfield. ^[26]

These measurements will help constrain the comet’s size, rotation, and composition — offering a rare laboratory for studying material formed around another star.

NASA vs alien rumours

3I/ATLAS has also become a magnet for fringe speculation.

On 19 November, NASA held a briefing and released new images, while explicitly rejecting claims that the object is alien technology. A Reuters report quotes NASA officials saying they see no “technosignatures” and that 3I/ATLAS “looks and behaves like a comet” in every respect. ^[27]
Commentaries and opinion pieces, including work by Harvard astronomer Avi Loeb, have pointed out unusual aspects of its trajectory and activity and proposed exotic possibilities, including speculative ideas about technological “thrusters.” ^[28]

At the same time, mainstream astronomers emphasize that comets can exhibit complex jets, brightness changes, and non‑gravitational accelerations due to outgassing — especially for an interstellar first‑timer that may host unusually volatile ices. ^[29]

Today, several outlets are trying to tamp down the wilder claims:

LehighValleyNews.com’s “Watching the Skies: Nov. 23–29 | Interstellar comet fuels online misinformation”highlights how viral posts have overstated the risk and “alien” angle, reiterating NASA’s view that there is no evidence of danger or artificial origin. ^[30]
A CityNews Vancouver podcast episode released 24 November frames the object as a “cosmic rock or an alien threat?” but ultimately leans on NASA scientists who call it an ordinary — though extremely interesting — comet. ^[31]

In short: 3I/ATLAS is a faint, challenging telescopic target and a scientific gold mine — not a doomsday object.

Other Telescopic Comets: SWAN and Wierzchos

C/2025 R2 (SWAN)

C/2025 R2 (SWAN) is a long‑period comet discovered in September 2025 in SWAN images from the SOHO spacecraft. ^[32]

It peaked near magnitude 6 in September and around its 20 October closest approach to Earth (~0.26 AU), making it briefly naked‑eye under dark skies. ^[33]
By 21 November, it had faded to about magnitude 10, still visible in 20×80 binoculars and small telescopes, and now sits roughly 10° to the upper left of Saturn after sunset for northern observers. ^[34]
Ephemerides for 24 November show it around magnitude 10.6, at RA ~23h51m, Dec +7°, well placed in the evening sky for mid‑latitudes. ^[35]

It’s fading but climbing higher, and December sky diaries describe it as “fading but getting higher in the sky”, making it a pleasant quarry for backyard telescopes. ^[36]

C/2024 E1 (Wierzchos)

C/2024 E1 (Wierzchos) is a fainter, more patient‑observer target:

StarWalk’s comet guide notes it should be visible in small telescopes and binoculars in autumn 2025, mainly for northern observers, before moving too close to the Sun ahead of its January 2026 perihelion. ^[37]
TheSkyLive and astro.vanbuitenen ephemerides put it around magnitude 11.8 on 24 November, in Ophiuchus, with a small elongation of about 27° from the Sun — meaning it’s embedded in evening or morning twilight and not easy even for experts. ^[38]

Realistically, E1 is best left to experienced imagers with GoTo mounts and darker skies, at least until it brightens further into early 2026.

December 2025: What’s Next for These Comets?

Looking beyond tonight, here’s what the coming month is likely to bring:

3I/ATLAS
- According to NASA’s dedicated page, the comet disappeared into solar glare after September and reappears on the far side of the Sun in early December, allowing renewed ground‑based observations. ^[39]
- Through December it travels from Virgo into Leo, fading from about magnitude 10–11 toward 12+. ^[40]
C/2025 K1 (ATLAS)
- December forecasts from northern‑latitude observing groups say K1’s fragments will be circumpolar and observable all night, though fainter night by night as the debris spreads and the comet recedes. ^[41]
C/2025 R2 (SWAN)
- Continues to fade, but climbs higher in the evening sky, particularly useful for telescopes as long as it remains around magnitude 11 or brighter. ^[42]
C/2025 A6 (Lemmon)
- Will drift closer to the Sun in our sky and likely disappear into twilight for most casual observers by mid‑December, while still being a rich target for photographers and southern observers as geometry changes. ^[43]
24P/Schaumasse and C/2024 E1 (Wierzchos)
- Both will continue slowly brightening, heading toward their early‑2026 peaks near magnitude 8–9, but remain relatively faint in December, best tackled with larger telescopes and imaging gear. ^[44]

How to See These Comets from Your Location

Because visibility windows depend heavily on where you are, use these general steps:

Use an app or online ephemeris
- Sites like TheSkyLive and apps like SkySafari, Stellarium, or similar let you enter your location and load each comet (e.g. “C/2025 A6”, “C/2025 K1”, “3I/ATLAS”). They’ll show altitude, direction, and a finder chart for your exact time and place. ^[45]
Choose the right targets for your gear
- Unaided eye / basic binoculars (7×50, 10×50):
  - Focus on C/2025 A6 (Lemmon) and possibly C/2025 R2 (SWAN) under truly dark skies.
- Small telescope (80–120 mm or 6–8″ Dob):
  - Add C/2025 K1 (ATLAS) and 3I/ATLAS.
- Larger telescopes / imaging setups:
  - Try C/2024 E1 (Wierzchos) and 24P/Schaumasse as well.
Plan around the Moon
- For fainter comets like K1, R2, and 3I/ATLAS, wait for moonless windows or observe when the Moon is below the horizon. Sky & Telescope notes that early December offers some Moon‑free mornings and evenings ideal for K1 and 3I/ATLAS. ^[46]
Dark skies and patience
- Comets rarely look like the dramatic photos you see online. Expect subtle, fuzzy patches that become more obvious the longer your eyes stay dark‑adapted.

Are Any of These Comets Dangerous?

Short answer: No.

3I/ATLAS never comes closer than about 1.8 AU (269 million km) to Earth on 19 December 2025 — nearly twice the Earth–Sun distance. ^[47]
C/2025 K1 (ATLAS)’s closest approach is about 0.40 AU on 25 November, still over 60 million km away. ^[48]
C/2025 R2 (SWAN) has already passed perigee at 0.26 AU with no issues, and its orbit is now carrying it away. ^[49]

NASA and independent orbit calculators agree that none of the current comets pose any impact threat or significant hazard — they’re purely observational treats. ^[50]

The Big Picture: Why This Season of Comets Matters

From an observer’s point of view, late 2025 is a rare feast:

A naked‑eye green comet (Lemmon) in the twilight.
Multiple binocular and telescopic comets — SWAN, K1, E1, and more.
An interstellar visitor, 3I/ATLAS, being imaged simultaneously from Earth, Mars, and space telescopes, while also driving a global conversation about how we interpret surprising data. ^[51]

If you have even modest gear and reasonably dark skies, the next few weeks are an excellent time to start (or reboot) a comet‑hunting habit. Start with Lemmon after sunset, chase K1 and 3I before dawn, and let the fainter iceballs be your excuse to learn the sky more deeply.

3I/ATLAS is Speeding Up! Now Visible Near Mercury Through Home Telescopes!