NASA — The Hubble Space Telescope has captured the sharpest-ever image of comet 3I/ATLAS, marking a groundbreaking moment in the study of interstellar visitors.

Traveling at an astonishing 130,000 mph, the comet is only the third known interstellar object to pass through our solar system. Hubble’s observation on July 21, 2025, made from a distance of 277 million miles, revealed the comet could be as small as 1,000 feet in diameter — far smaller than earlier estimates of several miles.

Originating from another star system, 3I/ATLAS offers scientists an extraordinary opportunity to study materials formed beyond our Sun’s reach. The comet will make its closest approach near Mars in late October 2025, posing no threat to Earth but providing a prime vantage point for further research.

Peer-reviewed studies, including those in the Astrophysical Journal, note that the analysis of such objects can deepen our understanding of planetary formation diversity and the chemical makeup of distant solar systems.