Astronomers are on the verge of unraveling the mysteries of the interstellar comet 3I/ATLAS as it travels through our solar system. This comet, first spotted in late June and confirmed by NASA in July, is intriguing because it comes from beyond our solar neighborhood. Unlike similar visitors like 1I/’Oumuamua and 2I/Borisov, 3I/ATLAS is possibly the largest, measuring between 3 to 7 miles wide.
Right now, the comet is taking a fascinating journey through our inner solar system. It’ll make a close pass by the sun on October 30 and continue towards interstellar space, passing Jupiter in March 2026. Fortunately, there’s no risk to Earth.
While tracking its path is straightforward, determining where it originated is more complex. Traveling at an astonishing speed of 130,000 miles per hour, 3I/ATLAS has been influenced by the gravitational pull of many stars along its journey. New research published on arXiv sheds light on the comet’s origins. Using data from the retired Gaia space telescope, scientists traced its path back over 4 million years, identifying 62 nearby stars it might have encountered. Surprisingly, none of these stars significantly altered its course, suggesting a very distant origin.
According to lead author Xabier Pérez-Couto, this could mean that 3I/ATLAS hails from the galactic frontier, a region where older and younger stars converge. If true, this comet could be around 10 billion years old—much older than our sun, which formed about 4.6 billion years ago. It may even be a glimpse into the early Milky Way, offering a valuable time capsule of cosmic history.
Galaxies like the Milky Way contain stars in different layers, known as the thin and thick disks. The thin disk hosts younger stars, rich in heavy elements, while the thick disk consists of older stars with fewer such elements. 3I/ATLAS could be from the edge of these disks, linking it to the galaxy’s early environments, which have long since stopped forming new stars.
Despite the promising findings, this research has its limits. It only considers stars nearby, meaning 3I/ATLAS’s exact birthplace remains a mystery. As it continues its journey, scientists on Earth and missions around Mars and Jupiter will get a closer look, hoping to uncover its secrets and what it can teach us about our galaxy’s past.
For further details, check out NASA’s official page and the research on arXiv.
