Astronomers have made a groundbreaking discovery about an interstellar comet that blazed past the Sun last year. The research suggests that the comet 3I/Atlas could be as old as 12 billion years, making it potentially the most ancient object ever discovered within our solar system's vicinity.
Scientists used observations from NASA's James Webb space telescope and the Alma observatory in Chile to determine the comet's isotopic ratios. These measurements revealed a distinct elemental composition unlike any known body originating within our own solar system.
The key finding was an exceptionally high concentration of deuterium, a heavier isotope of hydrogen, found to be 10 times greater than in comets from our own solar system. This suggests that 3I/Atlas formed in extremely cold conditions, at temperatures as low as -243°C, making it one of the coldest objects ever observed within our solar system.
The origin point of 3I/Atlas remains a mystery, but interstellar objects are believed to form similarly to our own comets during the violent birth of new planets. This comet has likely been drifting through our galaxy for billions of years before its brief encounter with the Sun.
3I/Atlas is only the third interstellar visitor humanity has observed, following 1I/'Oumuamua in 2017 and 2I/Borisov in 2019. Its unusual brightness provided an unprecedented opportunity for scientists to gather isotopic evidence, which was not possible with previous objects. While some speculation suggested it could be an alien spacecraft, NASA and the Seti Institute have dismissed this, finding no evidence of extraterrestrial technology.
As 3I/Atlas departs our solar system, astronomers anticipate spotting more interstellar objects in the coming years, thanks to new observatories like the Vera C Rubin observatory in Chile. This promises an exciting new field of study, offering profound insights into the formation and evolution of our galaxy.