Will Comet C/2025 R3 (PanSTARRS) be the 'great comet' of 2026?

A green ball of light showing comet Lemmon streaks across an orange and black night sky full of stars.

Comet C/2025 A6 (Lemmon) as seen over Málaga, Spain, on Oct. 1, 2025. (Image credit: Javier Zayas Photography/Getty Images)

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Distance and brightness
When and where to see it
How was it discovered?
A cluster of comets

After the excitement of three visible comets in 2025, another may put on a show in late April 2026. However, although the comet, known as C/2025 R3 (PanSTARRS), could become bright enough to be seen with the naked eye, it could just as easily remain visible only through binoculars and telescopes.

In the wake of Comets C/2025 A6 (Lemmon) and C/2025 R2 (SWAN) in October, Comet R3 (PanSTARRS) is due to reach perihelion — its closest point to the sun — on April 20, 2026. On that date, this icy visitor to the inner solar system will come within 47.4 million miles (76.3 million kilometers) of the sun.

That's between the orbits of Mercury and Venus, or between 29 million and 67 million miles (47 million to 108 million kilometers), on average. On April 27, Comet C/2025 R3 (PanSTARRS) will be at its closest point to Earth — within 44 million miles (70.8 million km) — and so will probably be at its brightest.

Comet C/2025 R3 (PanSTARRS) distance and brightness

A map of our solar system using different colored rings for the planets' orbits and in white a label showing the path of comet Panstarrs — The orbital path of Comet C/2025 R3 (PanSTARRS) through the inner solar system. (Image credit: JPL Small-Body Database Lookup)

The brightness of comets is notoriously unpredictable. Although Comet C/2025 R3 (PanSTARRS) could prove to be the brightest comet of 2026, it's not known how bright it will get. Some predict it could reach magnitude 8, which is about the same brightness as Neptune — too faint to be seen with the naked eye but easy to spot in binoculars or a small telescope. Others predict Comet C/2025 R3 could reach a brightness of magnitude 2.5. That's comparable to the brightest stars in the famous W-shaped constellation Cassiopeia, which is easily visible with unaided eyes in a dark sky.

Comet R3's prospects of becoming a bright, easy-to-see nighttime object may be enhanced by a phenomenon called forward scattering. Because this comet will move between Earth and the sun, its tail will reflect and scatter a lot of sunlight in the direction of Earth — and into the eyes of observers — in late April 2026.

When and where to see Comet C/2025 R3 (PanSTARRS)

A star map showing the great square of Pegasus and various stars and objects labeled, including the moon. Inside the square is a labeled dot for Comet Panstarrs — Comet C/2025 R3 (PanSTARRS) an hour before sunrise on April 13, 2025, as seen from midlatitudes of the Northern Hemisphere. (Image credit: Starry Night)

Comet C/2025 R3 (PanSTARRS) will be at its best in the predawn sky in late April, as seen from the Northern Hemisphere, and after sunset in early May for viewers in the Southern Hemisphere. It will reach perihelion in the constellation Pisces, just beneath the Great Square of Pegasus.

When Comet R3 (PanSTARRS) brightens in the night sky, there will likely be some interference from moonlight, but darkness will prevail close to perihelion. A new moon on April 17, 2026, bodes well for the comet's post-sunset perihelion on April 20. But at its closest point to Earth on April 27, it will likely be lost in the sun's glare.

Around April 13-15, the comet will be within the Great Square of Pegasus, around 15 degrees above the eastern horizon, an hour before sunrise, as viewed from mid-northern latitudes. There will be a close to a waning crescent moon for a few mornings.

Discovery of Comet C/2025 R3 (PanSTARRS)

Comet C/2025 R3 (PanSTARRS) was discovered on Sept. 8, 2025, by Pan-STARRS, a pair of 1.8-meter (5.9 feet) reflector telescopes atop Haleakalā volcano in Hawaii. Pan-STARRS constantly takes wide images of the sky, and then software compares them with older images, flagging anything that moves. Follow-up observations using the 3.6-meter (11.8 feet) Canada-France-Hawaii Telescope at Mauna Kea, Hawaii, on Sept. 17 helped astronomers calculate the comet's path.

A cluster of comets

A bright green comet is pictured to the bottom left of a starfield against a black sky, with a long tail extending to the upper right of the screen. — Comet Lemmon captured on Sept. 20, 2025. (Image credit: Dan Bartlett)

After a few barren years in the wake of Comet C/2020 F3 (NEOWISE), six notable comets made their mark in 2024 and 2025. First, there was the "Devil Comet" 12P/Pons-Brooks" (also dubbed the "Mother of Dragons" comet) in April 2024. Then came Comet C/2023 A3 (Tsuchinshan-ATLAS) in October 2024 and the bright C/2024 G3 (ATLAS), the "New Year comet," which put on a great show for viewers in the Southern Hemisphere in January 2025. It was followed in mid-October by Comet C/2025 A6 (Lemmon), which reached the cusp of naked-eye visibility and, to a lesser extent, Comet C/2025 R2 (SWAN).

That's not to mention 3I/ATLAS, only the third interstellar object ever to visit the solar system, after 'Oumuamua in 2017 and 2I/Borisov in 2019. 3I/ATLAS came closest to the sun on Oct. 29 during its trip through the solar system and then rapidly brightened, baffling scientists.

Will Comet C/2025 R3 (PanSTARRS) become a "great comet" in 2026? Only time will tell.

Jamie is an experienced science, technology and travel journalist and stargazer who writes about exploring the night sky, solar and lunar eclipses, moon-gazing, astro-travel, astronomy and space exploration. He is the editor of WhenIsTheNextEclipse.com and author of A Stargazing Program For Beginners, and is a senior contributor at Forbes. His special skill is turning tech-babble into plain English.

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