How far away is interstellar comet 3I/ATLAS from Earth on December 17? Latest coordinates

Interstellar comet 3I/ATLAS is making its last approach toward Earth this week, with experts tracking its position as it passes through the inner solar system. As of December 17, 2025, the comet is at about 1.8 astronomical units (AU), or about 167,286,110 miles, from Earth, with a magnitude of 12.5, according to the data shared on the Solar System Dynamics. 

Presently, it is in the constellation Leo at Right Ascension 10h 55m 31s and Declination +06° 16’ 24”. Due to this enormous distance, reflected light from the comet takes almost 15 minutes to reach us. As per Sky Live, this celestial object, scheduled to make its closest approach to Earth on December 19, will grace our sky at a distance of about 167,171,912 miles.

For astronomers who follow the object, the comet will be at a Right Ascension of 10h 53m 15s and a Declination of +06° 28’ 00” on Thursday, December 18. At this time, the object will have a magnitude of 15.16 as it journeys through the constellation Leo. By Friday, December 19, 3I/ATLAS will make its closest approach to Earth. Its coordinates at that time will be Right Ascension 10h 48m 38s and Declination +06° 51’ 39”. Although it will be at the closest possible distance to Earth, its brightness is predicted to be 15.19, which means it will be a challenging target for anything but powerful telescopes. 

Because the comet is so faint, it will only be able to be seen via a telescope with at least 30 centimeters of aperture, NASA said. For the best viewing results, stargazers should focus on the east-to-northeast sky during the pre-dawn hours. The comet can be found positioned just below Regulus, the brightest star in the constellation Leo, which serves as a helpful celestial landmark for those scanning the area. 

3I/ATLAS stands out in a year filled with several celestial discoveries. First spotted by the ATLAS team on July 1, it is only the third interstellar object ever confirmed to enter our solar system. Researchers believe this ancient wanderer has been drifting through deep space for billions of years, making it even older than our own solar system. While 3I/ATLAS is a rare guest from beyond, several other comets have made headlines throughout 2025. C/2025 R2 (SWAN) was discovered in early September by observer Vladimir Bezugly in images provided by the SWAN instrument aboard the SOHO spacecraft. It skirted past the Sun on September 12 and made its close approach to Earth on October 20, passing within 24.2 million miles of our planet.

Another object, C/2025 A6, was reportedly discovered by the Mount Lemmon Survey on January 3, 2025. It came closest to Earth on October 21, remaining about 55.4 million miles away. When the comet's orbit was looked into by scientists, it was found that the comet had last visited the inner solar system more than a millennium ago. As for 3I/ATLAS, it will never return. 

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