Visitor from Outside the Solar System May Be 7 Billion Years Older Than the Sun

The James Webb Space Telescope has revealed exceptional chemical characteristics in the comet 3I/ATLAS, which arrived from outside our solar system, opening a new window for understanding the conditions under which icy bodies formed around other stars.

Discovered in July 2025, the comet is the third confirmed object originating from interstellar space.

Last December, a scientific team led by Nathan Roth from The American University in Washington used the James Webb Telescope to observe the comet and analyze the methane gas it emits.

Results published in the journal Nature Astronomy showed that the ratio of deuterium, known as heavy hydrogen, in the methane is approximately 14 times higher than the ratio measured in comet 67P, the only comet from our solar system for which similar measurements are available.

Researchers suggest that the ice of this visitor formed in an extremely cold environment exposed to high levels of cosmic radiation.

These findings reinforce a previous study published in the journal Nature in June 2026, which indicated that the comet’s age could be between 10 and 12 billion years, making it billions of years older than the Sun.

Despite the significance of the discovery, scientists emphasize that studying a single comet is insufficient to determine the general chemical characteristics of comets originating from other stellar systems.