The comet 3I/ATLAS is exiting our inner solar system and you can track it live thanks to NASA. Discovered by the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope network, 3I/ATLAS is the third ever interstellar object to visit the solar system after Oumuamua (2017) and Borisov (2019).
As the ATLAS survey network in Río Hurtado, Chile, was scanning through the sky, it identified a hazy small heavenly body travelling at an unusually fast speed on July 1. This wasn’t just any native asteroid or comet because its orbit was too steep and the speed was also too high (about 60 km/second). Besides, it did not follow a closed orbital path about the Sun. That ‘hyperbolic trajectory’ is what gave away its identity.
On December 20, NASA released new pictures of this icy visitor captured by various spacecraft around Mars and beyond.
How to track 3I/ATLAS live?
Yes! You can follow comet 3I/ATLAS as it speeds through the solar system. Here’s how:
While it’s not visible to the naked eye, you can track its real-time path using @NASA’s interactive tool, Eyes on the Solar System.
🔗: https://t.co/kV5kQEThkF pic.twitter.com/26yAb97k4K
— NASA Science (@NASAScience_) November 19, 2025
The comet reached perihelion (closest point to the Sun) on October 30 and is currently cruising on its hyperbolic trajectory out of the solar system. It is estimated to make its closest approach to Earth on December 19 and you can track its live location using NASA’s interactive tool Eyes on the Solar System that keeps eyes on every major object – asteroids, comets and spacecraft – in our solar neighbourhood.
NASA’s observation campaign
NASA has placed multiple eyes in the sky to observe the interstellar object, perhaps at a scale never seen before. During a live press conference earlier today, the agency shared pictures captured by the Mars Reconnaissance Orbiter, SPHEREx telescope, the Solar and Heliospheric Observatory (SOHO), the Psyche spacecraft, exoplanet-hunter TESS, the STEREO-A telescope, Lucy spacecraft and Mars Perseverance rover.
Explaning the need for attention and investment into studying it, NASA said, “By observing the comet from so many locations, NASA has an opportunity to learn about the ways that 3I/ATLAS differs from our solar system’s home-grown comets and give scientists a new window into how the compositions of other systems may differ from.”
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3I/ATLAS size and speed
This comet has some very interesting characteristics. When it was first spotted, 3I/ATLAS was travelling at a speed of 137,000 miles per hour (221,000 km per hour). As the Sun pulled the comet inward, it changed gear and its speed increased to about 153,000 miles per hour (246,000 km per hour) during perihelion. When 3I/ATLAS leaves our solar system, NASA says, it will travel at the same speed as it came in.
NASA’s Hubble Space Telescope observed the interstellar comet on August 20 and astronomers have based its size on the findings from the telescope. The estimated diameter of 3I/ATLAS’ nucleus is no less than 1,400 feet (440 meters) and no greater than 3.5 miles (5.6 km). In comparison, 1I/ʻOumuamua’s size was between 100 to 440 m, and 2I/Borisov was almost 1 km wide.
ALSO READ: NASA Finally Releases Comet 3I/ATLAS Images Captured From Mars & Beyond
