A new study finds that 3I/ATLAS may be 10 to 12 billion years old. In comparison, our solar system is only 4.6 billion years old - a relative newcomer.
The study used infrared measurements from the James Webb Space Telescope (such as the picture above) to measure the ratio of deuterium (heavy hydrogen, containing one neutron and one proton) to regular hydrogen (just one proton). The researchers found that it was almost 1% - more than ten times higher than in comets that are confined to our solar system. It also contained a higher ratio of carbon-12 (6 protons + 6 neutrons) to carbon-13 (6 protons + 7 neutrons) than is typically found in objects in our solar system. This is evidence that it formed in a 'metal-poor' environment. n. b. Astronomers define any object heavier than helium to be a 'metal.' They also concluded that 3I/ATLAS formed at very low temperatures, less than 30 Kelvin (-405 Fahrenheit).
The measured carbon ratio is consistent with formation in the early universe, when there were less heavy elements around than there are today, while the high level of deuterium points to formation in a cold environment. Both of these connections are not trivial, relying on more complex comparisons; for more details, please read the paper, which is open access.
