"Anti-Tail" And Odd 594-Kilometer Feature Found On Interstellar Object 3I/ATLAS By Keck Observatory October 16, 2025
Astronomers analyzing observations of interstellar comet 3I/ATLAS using the W. M. Keck Observatory have discovered further unusual features of our third interstellar visitor, and confirmed the presence of a rare "anti-solar tail". On July 1, 2025, astronomers at the Asteroid Terrestrial-impact Last Alert System (ATLAS) spotted an object making its way through our Solar System. That's no surprise, given the name. What was unusual, and highly interesting, was that the object appeared to be the fastest object of this type ever observed, and had an eccentricity of between 6.1 and 6.2.
An eccentricity greater than 1 means it is an interstellar visitor, the third we have found so far, and will leave our Solar System once more.
