Every few years a small, dark body of ice and stone swings close to the Sun and then loops back out into the cold, and each return is a chance to look at something older than the planets. Comet 11P/Tempel-Swift-LINEAR reaches its nearest point to the Sun on November 9, 2026, and two days later passes within about 60 million kilometers of Earth, arranged in the sky in a way it rarely is. Its path has been shaped by three astronomers who found it at different times and by Jupiter's gravity over the last century. For those with a telescope in the northern hemisphere, it offers a faint, patient gl
Comet 11P/Tempel-Swift-LINEAR Reaches Perihelion, Offering Northern Observers a Rare Well-Placed View
A comet the size of a city park, close enough to watch for one week
Mark
Why does this comet matter if it's only magnitude 13?
Mimi
Because of the geometry. It sits nearly opposite the Sun, high in Taurus at midnight, which is the best alignment it has had in the modern era.
Mark
And the name carries a story?
Mimi
Three of them. Tempel in 1869, Swift in 1880, and the LINEAR survey in 2001, which found it again as an unknown object.
Luke
Worth noting the 13.3 is a prediction. Comets can outburst or fade, so nobody knows what observers will actually see.
Mark
What do you need to see it?
Mimi
At least a 150mm telescope, or a smart telescope that stacks exposures. Binoculars won't do it under suburban skies.
Luke
And the tail is only a maybe, photographically, if the comet is active. The source doesn't promise one.
Mark
What does the science add?
Mimi
Rosetta's work on 67P, a related comet, showed nuclei are rubble piles from the early solar system, so each perihelion exposes fresh material.
Luke
That's about the class of comets, though. Nothing here says 11P itself is being measured by a mission this week.
Mark
And if people miss it?
Mimi
Early 2032 is the projected next perihelion, but that return's geometry isn't worked out yet.
Il Polso
- A 1.2-kilometer ball of ice reaches perihelion on November 9, 1.387 AU from the Sun, warming its surface into a glowing coma.
- On November 11 it closes to 0.4012 AU, about 156 times the Earth-Moon distance, and the window for watching it is short.
- At magnitude near 13.3, it is invisible to the naked eye and demands at least a 150mm telescope or a smart telescope.
- Its brightness is uncertain: it could outburst by a magnitude or fade if its volatiles have been depleted by earlier passes.
- Observers are racing to chart its moving position against Aldebaran and the Pleiades before the prime window closes around November 15.
- The next perihelion is not until early 2032, so northern skywatchers may have their best chance for years right now.
Every few years a small, dark body of ice and stone swings close to the Sun and then loops back out into the cold, and each return is a chance to look at something older than the planets. Comet 11P/Tempel-Swift-LINEAR reaches its nearest point to the Sun on November 9, 2026, and two days later passes within about 60 million kilometers of Earth, arranged in the sky in a way it rarely is. Its path has been shaped by three astronomers who found it at different times and by Jupiter's gravity over the last century. For those with a telescope in the northern hemisphere, it offers a faint, patient glimpse of how the early solar system still survives in the present.
On November 9, 2026, a dark body of ice and rock about 1.2 kilometers across reaches the closest point to the Sun on its loop of roughly six years. It is Comet 11P/Tempel-Swift-LINEAR, and for northern observers with a telescope, the days around perihelion are the best chance in about six years to see it.
The comet sits well beyond Earth's orbit at its nearest point, but close enough for the ices in its nucleus to warm and feed a glowing coma. Two nights later, on November 11, it comes within about 60 million kilometers of Earth. The night of November 11 into 12 offers the single best opportunity, within a window stretching from November 9 to about November 15.
The geometry is what makes this return special. The comet lies nearly opposite the Sun in the sky, rising near sunset and crossing high overhead around midnight. Observers across the continental United States, Canada and Europe are well placed, while southern viewers get less favorable views.
It will never be visible to the naked eye. A telescope of at least 150mm aperture is the practical minimum, and smart telescopes can reach its faint magnitude with stacked exposures, provided the observer tracks its moving position rather than the stars. Aldebaran and the Pleiades serve as guideposts.
The comet's name joins three astronomers. Ernst Tempel found it in 1869, Lewis Swift caught it independently in 1880 without knowing it was the same object, and the LINEAR survey detected it again in 2001. Jupiter's encounters between 1900 and 1946 reshaped its orbit, and it now belongs to the family of comets driven by that giant planet.
Each pass sends sunlight into its ices, releasing gas that drags dust outward into the glowing coma. Those materials are remnants of the early solar system. Brightness, however, remains the open question: the comet may outburst or underperform, and the next perihelion is not expected until early 2032.
On November 9, 2026, a ball of dark ice and rock about 1.2 kilometers across reaches the nearest point to the Sun on its 5.95-year loop. It is Comet 11P/Tempel-Swift-LINEAR, and for northern hemisphere observers with a telescope, the days around perihelion are the best chance in about six years to watch it.
The comet passes to within 1.387 astronomical units of the Sun, still farther out than Earth, but near enough for the ices in its nucleus to warm and feed a coma. Two nights later, on November 11, it makes its closest approach to Earth at 0.4012 AU, about 60.02 million kilometers (37.3 million miles), or roughly 156 times the Earth-Moon distance. Its speed relative to Earth at that point is 7.9 km/s. The night of November 11 into 12 is the best single opportunity, within a prime window running from November 9 to about November 15.
The geometry is what makes this return unusual. The comet sits at a solar elongation of 170 degrees, nearly opposite the Sun, at a declination of +26.3 degrees in Taurus. It rises near sunset, crosses high overhead around midnight, and sets near sunrise. That is the best alignment it has had in the modern observing era, and better than many past returns, when it lay closer to the Sun in the sky and fought twilight. Observers across the continental United States, Canada and Europe are well placed; southern hemisphere viewers get less favorable geometry.
It will not be a naked-eye object. Predicted peak magnitude is about 13.3, so a telescope of at least 150mm (6-inch) aperture is the practical minimum. Under dark skies with 200mm or larger, observers should see a small fuzzy patch with a brighter central condensation. Smart telescopes such as the Unistellar Odyssey, Vaonis Stellina and ZWO Seestar series can reach magnitude 13 to 15 with stacked exposures, though users should track the comet's ephemeris position rather than the stars, since it moves noticeably during a session. Finder charts are available from JPL Horizons, TheSkyLive, SkySafari, Stellarium and Cartes du Ciel, with Aldebaran and the Pleiades as guideposts. Photographers can try 60 to 300 second exposures on a tracking mount and stack them in DeepSkyStacker or Siril, aligned on the comet.
The comet's history spans three astronomers. Ernst Wilhelm Leberecht Tempel found it from Marseille on November 27, 1869. Lewis Swift independently caught it from the Warner Observatory in Rochester, New York, on October 11, 1880, without knowing it was the same object; orbital calculation later linked the two sightings. Then it went unobserved until December 7, 2001, when the LINEAR survey, an MIT Lincoln Laboratory patrol using a 1.0-meter telescope in New Mexico, detected it as P/2001 X3. Prediscovery images from September and October 2001 helped establish its identity, and the permanent name joined all three discoverers.
Between 1900 and 1946 Jupiter reshaped its orbit through four encounters: May 1911 at 0.61 AU, July 1923 at 0.50 AU, April 1935 at 0.56 AU, and a more distant pass in November 1946 at 1.33 AU. Those encounters altered its period and perihelion distance. 11P is a Jupiter-family comet, with a Tisserand parameter of 2.839, inside the 2.0 to 3.0 range for the class. The Minor Planet Center had catalogued more than 430 numbered members as of 2025. They originate in the Kuiper Belt and scattered disc and migrate inward via the centaurs.
At perihelion, sunlight makes surface ices sublimate, mostly water, along with carbon dioxide, carbon monoxide and organics. Escaping gas drags dust outward to form the coma, which is what telescopes see, not the nucleus. ESA's Rosetta mission to the related comet 67P/Churyumov-Gerasimenko showed such nuclei to be primordial rubble piles, so each pass exposes material from the early solar system.
Brightness is the caveat. Comets can outburst by a magnitude or more, or underperform if earlier passes depleted their accessible volatiles. The 13.3 figure is a best estimate. Its perihelion distance also means it will never rival Hale-Bopp or Neowise. The next perihelion is projected around early 2032, with geometry not yet calculated in detail, so this return may be the better one for northern observers.
Citazioni salienti
The ~13.3 predicted magnitude is a best estimate, not a guarantee.— Tech Times
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