cometary-science

Interstellar comet 3I/ATLAS was almost called 3I/Rubin, after researchers found that the giant survey telescope coincidentally spotted this visitor from the stars over a week before it was officially discovered.

When the interstellar comet 3I/ATLAS passed between ESA’s Jupiter Icy Moons Explorer (Juice) spacecraft and NASA’s Europa Clipper spacecraft in November 2025, scientists seized an once-in-a-lifetime chance: one spacecraft caught the comet’s glowing dayside, the other its dusty night side, simultaneously. The post Europa Clipper and Juice Team Up to Observe Interstellar Comet 3I/ATLAS appeared fir…

Looking for a sky event this week? Check out our full Sky This Week column.  May 9: Look the croc in the eye Although still best for experienced observers with larger scopes, Comet 10P/Tempel (also called Tempel 2) is quickly brightening. Glowing at roughly magnitude 15, Tempel 2 is currently in Aquila the Eagle, rising late in Continue reading "The Sky Today on Sunday, May 10: Can you catch Come…

In September 2012, Russian astronomers Vitali Nevski and Artyom Novichonok discovered Comet C/2012 S1; as they were using a telescope from the International Scientific Optical Network, the comet was named ISON. Comet ISON was a new visitor from the Oort Cloud, making its first trip to the inner solar system. With the typical build of Continue reading "May 8, 2013: The promise of Comet ISON" The p…

The Subaru Telescope observed the interstellar comet 3I/ATLAS (C/2025 N1) on January 7, 2026 (UT), after it made its closest approach to the Sun. By observing colors in the coma around the comet, astronomers could estimate the ratio of carbon dioxide to water. This ratio is much lower than that inferred from earlier observations by space telescopes. These findings suggest that the chemistry of th…

Allen Hwang from Deming, New Mexico Before slipping into the morning twilight, Comet PanSTARRS put on a show April 18 as its ion tail took on a smoky, billowing appearance, likely due to a passing solar storm. The imager captured 7.5 minutes of exposure with an 11-inch RASA scope. The post A billowing tail appeared first on Astronomy Magazine .

The ion tail appeared as Comet C/2025 R3 PanSTARRS was about 45 million miles from Earth (72 million kilometers) during its closest approach.

A new analysis of data obtained by JWST on 3I/ATLAS as it was on its way out of the Solar System (in December 2025) showed that its interior is rich in methane ice.

The interplanetary comet 3I/ATLAS is remarkably rich in a specific type of water that contains deuterium, meaning it came from somewhere colder and with lower levels of radiation than our early Solar System.

Early in 1986, a visitor from deep space graced Earth’s skies, and for a few breathless weeks human eyes were snatched from their daily labors and fixated on the heavens. The object of this transitory public veneration was Halley’s Comet — the most famous, easily recognizable, and beloved of celestial wanderers. This icy interloper, officially Continue reading "Halley’s Comet through the ages" Th…

We’re one comet down, and one to go for spring season 2026. We recently wrote about prospects for sungrazer C/2026 A1 MAPS and comet C/2025 R3 Pan-STARRS in April 2026. While the bad news is, Comet A1 MAPS disintegrated like so many sungrazers before it during its blistering close perihelion passage on April 4th, comet R3 Pan-STARRS put on an amazing dawn showing for early rising astrophotographe…

The interstellar comet 3I/ATLAS changed significantly as it flew by the sun last fall, astronomers have discovered.

Comet C/2025 R3 PanSTARRS is days away from its close pass of the sun during an event known as perihelion.

Observations from the Subaru Telescope on January 7, 2026, revealed a surprisingly low carbon dioxide-to-water ratio, suggesting the composition of the interstellar comet 3I/ATLAS changed as it heated up near the Sun. The post Interstellar Comet 3I/ATLAS Shows Shifting Chemistry after Perihelion appeared first on Sci.News: Breaking Science News .

The Jupiter-bound spacecraft JUICE spotted the interstellar invader comet 3I/ATLAS spraying enough water into space to fill 70 swimming pools a day.

Comet C/2025 R3 is on a once-in-a-lifetime approach to the Sun, brightening rapidly and offering an unprecedented chance to see it with the naked eye. Don’t miss this rare celestial event!

A small comet has been spotted slowing down and then speeding up again – but in the opposite direction, which we have never seen before

A rare long-period comet returns after 170,000 years — here's how to find comet C/2025 R3 (Pan-STARRS) before sunrise this April, with key dates, viewing tips and the best mornings to look.

If we’re lucky, we’ll soon have bright comets at both dawn and dusk. While Comet PanSTARRS (C/2025 R3) may never achieve the hoped-for splendor of the sungrazer Comet MAPS, at least its future appears more certain. It passes perihelion at a relatively chill 74.6 million km (46.4 million miles) on April 19th, compared to a Sun-scorching 162,000 km (100,700 miles) for the MAPS comet. If they both p…

Get the world’s most fascinating discoveries delivered straight to your inbox. You are now subscribed Your newsletter sign-up was successful Want to add more newsletters? Join the club Get full access to premium articles, exclusive features and a growing list of member rewards. For the first time ever, an astronomer has witnessed a comet changing the speed and direction of its own spin, thanks to…