Martin Cordiner said the interstellar comet 3I/Atlas may be "maybe it’s the oldest object to have been observed in our solar system," after new observations pointed to an age of up to 12 billion years. The study, published in Nature, also found chemistry unlike any body in our solar system.
Those measurements came from the James Webb space telescope and the Alma observatory in Chile. Peter Vereš, who helped identify the comet at the International Astronomical Union’s Minor Planet Center, called the research "exciting."
Nature study on 3I/Atlas
Cordiner, the lead study author at Nasa’s Goddard Space Flight Center, said 3I/Atlas could be nearly three times older than our solar system, which formed about 4.5 billion years ago. He added that the comet may be the oldest object observed in our solar system.
The comet is the third visitor from beyond our solar system that humanity has observed. It was spotted in July last year, after 1I/'Oumuamua was spotted in 2017 and 2I/Borisov in 2019.
James Webb and Alma
The new analysis focused on isotopes detected by the James Webb space telescope and the Alma observatory in Chile. The study said the measurements reveal an elemental composition unlike any solar system body, including 10 times more deuterium than comets in our solar system.
Cordiner said, "That high abundance of heavy water can only really happen, according to our understanding of astrochemistry, in a very cold environment," and said the isotopic evidence suggests the comet formed at -243C, or -405.4F.
3I/Atlas and cosmic noon
The scientists said the comet likely spent billions of years on "vast unimaginable trajectories" around our galaxy. They also detected a strange lack of chemical enrichment, and said 3I/Atlas could be a relic from cosmic noon, when many stars were forming approximately 10 billion years ago.
The Search for Extraterrestrial Intelligence Institute said last month it found no evidence of extraterrestrial technology on the comet, ending speculation that it could be an alien spacecraft. Vereš said the comet is now leaving the solar system and will never return, leaving researchers with a rare bright target to study before it disappears from view.
