A newly discovered interstellar comet is racing through our solar system, and the first telescope to capture it may have been the newly commissioned Vera C. Rubin Observatory in Chile. The comet, designated 3I/ATLAS, marks only the third interstellar object ever confirmed to pass through our cosmic neighborhood—joining the ranks of ‘Oumuamua and Comet 2I/Borisov.
Rubin Observatory Catches A Cosmic Wanderer
As part of its initial test operations, the Rubin Observatory had its camera pointed at a region of the sky that, by chance, intersected with the path of 3I/ATLAS. On June 21, during what researchers described as “an act of cosmic serendipity,” Rubin’s powerful imaging system captured the interstellar object as it journeyed toward the Sun. Although the comet’s official discovery came later, these early snapshots have proven invaluable in confirming its interstellar nature and behavior.
The Rubin Observatory—named after the pioneering astronomer Vera C. Rubin—hosts the largest digital camera ever built for astronomy. Its massive 3.2-gigapixel sensor, roughly the size of a small car, is capable of producing highly detailed images of deep space. On June 23, the observatory released its first batch of public images, revealing a stunning mosaic of millions of stars and galaxies. Among these observations were signs of distant supernovas and galactic structures, making it clear that Rubin’s technology is poised to change how we see the universe.
Confirmation Of An Interstellar Origin
The comet’s identity was formally recognized by the International Astronomical Union’s Minor Planet Center on July 2, which confirmed that 3I/ATLAS originated from outside the solar system. Initial detection came from data collected by the Asteroid Terrestrial-impact Last Alert System (ATLAS) between June 25 and 29, and again on July 1. Around the same time, the Deep Random Survey telescope in Rio Hurtado, Chile, also observed the object.
Shortly afterward, astronomers from the Gemini North telescope in Hawaii provided a close-up view of the comet’s coma, revealing a hazy envelope of gas and dust surrounding the icy nucleus. This behavior strongly suggests that 3I/ATLAS shares characteristics with traditional comets despite its alien origin.
One standout feature of 3I/ATLAS is its estimated age. Early analysis suggests it is approximately two billion years older than the solar system itself, making it the oldest comet ever discovered. Its velocity is equally remarkable. According to a preprint study still awaiting peer review, 3I/ATLAS is moving at a hyperbolic speed of around 37 miles per second (60 kilometers per second)—significantly faster than its interstellar predecessors.
The Significance Of Rubin’s Early Images
Rubin’s early observations were documented in a recent paper published on arXiv, which includes 49 total images of the comet. Some images were omitted from the analysis due to being captured during alignment calibration phases, which left them slightly out of focus. Nineteen images were acquired during deliberate operations and offered sharp views of 3I/ATLAS’s comet-like features, such as its coma and movement pattern.
These high-quality images are especially important because they were taken by a precision instrument during the comet’s earliest observable phase. They offer scientists a head start in understanding its composition, trajectory, and behavior as it speeds through our system. This kind of early data is rarely available for interstellar visitors, and Rubin’s imaging capability may open new avenues for studying such fleeting cosmic encounters.