Photo: ssbcrack
Interstellar comet 3I/ATLAS, currently passing through the Solar System, has become the subject of detailed observations with the James Webb Space Telescope. Analysis shows that its surface has been completely transformed by galactic radiation, forming a dense irradiated crust that differs significantly from the material the comet originally consisted of in its native star system.
Researchers estimate that during roughly seven billion years of travel through the Milky Way, the comet absorbed streams of cosmic rays. This gradually converted carbon monoxide into carbon dioxide and altered the surface composition down to a depth of 15–20 meters. As a result, 3I/ATLAS is not a pristine remnant of its original planetary system, but a product of long-term exposure to interstellar space. According to lead researcher Romain Maggiolo of the Royal Belgian Institute for Space Aeronomy, these findings represent a paradigm shift in the study of interstellar bodies. He notes that such objects can no longer be viewed as untouched fragments from distant worlds but rather as evidence of matter evolving in deep space.
The comet is traveling at over 210,000 km/h and reached its closest point to the Sun on October 29. This passage heated its surface, causing ices to sublimate and produce a bright gas tail. Scientists believe sublimation is occurring mainly in the irradiated layer, although the Sun's heat may melt the crust enough to expose deeper, unaltered material.
Maggiolo’s team plans to compare observations taken before and after perihelion to determine whether the inner layers can be revealed. Preliminary estimates suggest that 3I/ATLAS may be the oldest interstellar object ever observed — around 7.6 billion years old, approximately three billion years older than the Solar System itself.
