By Deutsche Welle
The comet that passed by us from another star last year probably originated in a cold and isolated corner of the galaxy that had not yet formed its own solar system, astronomers reported this Thursday (04/24/2026).
He comet 3I/ATLAS He is only the third visitor interstellar confirmed and possibly the oldest. The Scientists estimate that it could be up to 11,000 million years oldmore than twice the age of the Sun.
The oldest known interstellar comet
A team led by University of Michigan used the ALMA observatory, in Chile’s Atacama Desert, to examine the comet last fall.
The wandering but harmless ice ball was discovered last summer, giving the POT and the European Space Agency to point several space telescopes at it as it flew over Mars in October and made its closest approach to Earth in December.
Now It is located well beyond Jupiteron its way to definitively leaving our solar system, and continues to be seen only by specialists.
Deuterium, the key to the cold origin
In it study, published in Nature Astronomy, Scientists claim to have detected extraordinarily high amounts of deuterium – or heavy hydrogen – in the comet’s water. That suggests that the comet originated in a considerably colder place – before that solar system’s star even formed– than our own cosmic environment, explained Teresa Paneque-Carreño of the University of Michigan.
While our Sun may have been surrounded by other newly formed stars during its gestation, he noted, this comet’s birth star may have been lonelier, resulting in less warming and cooler conditions.
Size, speed and destination of the 3I/ATLAS
The exact place of origin of the comet remains unknown. Observations from the Hubble Space Telescope place the size of its core between 440 meters and 5.6 kilometers. He walks away to 220,000 kilometers per hour.
Connecting all of these “pieces of the puzzle can give us insight into what planetary formation conditions were like in those early times,” Paneque-Carreño said in an email.
‘Oumuamua and Borisov: the other star travelers
He first known interstellar object to enter our celestial neighborhood –’Oumuamua– was discovered by a telescope in Hawaii in 2017. Comet 2I/Borisov followed in 2019, named after the Crimean amateur astronomer who first spotted it.
FEW (AP, University of Michigan, Nature Astronomy)
