2 days ago - By late August 2025, the coma of ... that the inner coma of 3I/ATLAS (within 5 arcseconds from the nucleus) appeared fan-shaped and slightly brighter on the Sun-facing side....

December 12, 2025 - New images taken with the Gemini North telescope in Hawaii confirm that the interstellar comet 3I/ATLAS has gotten brighter and greener since its close flyby of the sun in October.

Interstellar Comet 3I/ATLAS is fast racing towards the inner solar system. It now has a cometary tail and a bright coma. Fresh observations show that the comet is getting brighter, meaning it is becoming more active.

3 days ago - We acknowledge with thanks the comet observations from the COBS Comet Observation Database contributed by observers worldwide and used in this table to report recent comet observations. The following table lists today's rise, transit and set times of comet 3I/ATLAS from Greenwich, UK (all times relative to the local timezone Europe/London):

1 day ago - In late November and early December, X-ray telescopes XRISM and XMM-Newton observed the comet, revealing a diffuse X-ray glow around the comet nucleus. This makes 3I/ATLAS the first interstellar comet to have been observed in X-ray light.

October 30, 2025 - 3I/ATLAS Rapidly Brightens and Gets Bluer than the Sun Near Perihelion New images of the interstellar object 3I/ATLAS as it approached perihelion on October 29, 2025, reveal rapid brightening and a …

April 27, 2026 - Where is 3I/ATLAS Now? By now, 3I/ATLAS is at a distance of a billion kilometers or 6.7 times the Earth-Sun separation, well beyond Jupiter. Our interstellar visitor appears as a fading dot, similar …

2 weeks ago - Thanks to its larger size (about 1.3 kilometers, or 0.8 miles, across), 3I/ATLAS became far brighter than the first two interstellar visitors. It reached 9th magnitude at perihelion, on October 30, 2025, when it came nearest the Sun (though ...

November 7, 2025 - 30, and three sun-facing spacecraft collected images of the wanderer as it zoomed past our star. This imagery revealed that 3I/ATLAS underwent a " rapid brightening" that exceeds what is observed in most comets at similar distances to the sun.

... New images taken with the Gemini North telescope in Hawaii confirm that the interstellar comet 3I/ATLAS has gotten brighter and greener since its close flyby of the sun in October.

December 12, 2025 - Just before 3I/ATLAS became unobservable, Unistellar data showed an unexpected surge in brightness. This brightening exceeded predictions, hinting at either a sudden outburst of gas or an increase in surface activity.

February 6, 2026 - Observations of comet 3I/ATLAS by SPHEREx in December 2025 reveal organic molecules, a sharp brightening and the venting of ancient debris.

November 4, 2025 - These observations have revealed that 3I/ATLAS has undergone a major transformation while it was hiding out of view. Dr Zhang found that the interstellar object underwent a rapid brightening ahead of reaching perihelion and also took on a ...

March 7, 2026 - This animation shows PUNCH’s observations of Comet 3I/ATLAS from September 28 to October 10, 2025. At this time, the comet was between 231 to 235 million miles (372 to 378 million km) from Earth. Stars create streaks of light in the background as the comet moves across the sky.

April 13, 2026 - Oct 21: As the comet hid behind the Sun, Loeb hinted it could use the Oberth effect to change course unseen. Oct 29: 3I/ATLAS survived its close pass to the Sun, suddenly brightening.

November 7, 2025 - A researcher has captured comet 3I/ATLAS glowing green and hiding its tail in a new image from the Lowell Observatory's powerful Discovery Telescope as we enter a critical observation phase for the interstellar visitor.

May 8, 2026 - This outgassing can cause small perturbations, or very slight changes in their trajectories. Observations of 3I/ATLAS show that these perturbations were indeed small and compatible with this process.

November 4, 2025 - Recent observations of the interstellar object 3I/ATLAS show that it has developed a faint blueish hue, hinting at a potential color change. This is the third time experts have seen the comet's coloring shift since it was discovered.