Sign up to see the future, today
Can’t-miss innovations from the bleeding edge of science and tech
Deuterium, a stable and non-radioactive isotope of hydrogen that features a neutron in addition to the single proton in its core, is extremely abundant across the universe.
But when combined with tritium, a different hydrogen isotope that features not just one but two additional neutrons, it can kick start a powerful nuclear fusion reaction. Scientists hope to one day use these isotopes to generate an abundance of clean energy using advanced reactors.
So it shouldn’t come as a surprise that Harvard astronomer Avi Loeb — who has long posited that mysterious interstellar object 3I/ATLAS, which recently swung through the inner solar system for a brief visit, could be a piece of alien technology — is intrigued by recent findings that the interstellar object is teeming with the hydrogen isotope.
In a recent blog, Loeb pointed to two yet-to-be-peer-reviewed papers that found that 3I/ATLAS bears an unusually high concentration of deuterium.
Don’t get too excited yet. As the papers’ authors admit, the abundance of the intriguing isotope could far more easily be explained by natural processes spanning billions of years, casting doubt on the spicy hypothesis that 3I/ATLAS could be an alien spacecraft using a fusion reactor to propel itself.
The first paper, which was submitted for review at Nature Astronomy last week, saw an international team of researchers, including scientists from NASA’s Goddard Space Flight Center and Jet Propulsion Lab, analyze near-infrared spectroscopy data of the interstellar object recorded by the James Webb Space Telescope last year.
The team found an “unexpectedly high” deuterium to hydrogen ratio in methane molecules shed by the object, an “exceedingly rare detection of deuterated organic molecules in an interstellar object.”
They suggest that the unusual abundance of deuterium could be the “natural consequence of formation” in an extremely cold environment, such as the proto-planetary disk surrounding its potentially ancient home in another solar system.
“Thus, 3I/ATLAS formed in an environment very different from that in which our Sun and planets originated,” the team concluded.
A separate paper, submitted to the journal Nature earlier this month, lists many of the same coauthors as the other study and goes over the spectroscopic measurements in detail, finding that the “water in 3I/ATLS is enriched in deuterium” at an “order of magnitude higher than in known comets.”
“Such extreme isotopic signatures indicate formation at temperatures ≲ 30 Kelvin [-405 Fahrenheit] in a relatively metal-poor environment, early in the history of the Galaxy,” the paper reads. “When interpreted with respect to models for Galactic chemical evolution, the carbon isotopic composition implies that 3I/ATLAS accreted roughly 10–12 billion years ago, following an early period of intense star formation.”
Both papers support the existing theory that 3I/ATLAS may be billions of years older than even our own Sun.
“3I/ATLAS thus represents a preserved fragment of an ancient planetary system, and provides direct evidence for active ice chemistry and volatile-rich planetesimal formation in the young Milky Way,” they concluded.
Loeb, however, isn’t convinced of their conclusion. In his latest blog, he suggested that the “proto-planetary disks could not have been cooler than the cosmic microwave background at the time they formed, which at a redshift of [around ten] had a temperature of 30 degrees Kelvin.”
“Hence, an important question arises: since deuterium is fusion fuel, might its over-abundance in 3I/ATLAS flag a technological signature?” he wrote, abruptly ending his post with a wildly speculative cliffhanger.
More on 3I/ATLAS: Please Resist the Urge to Drink the Melted Sludge From 3I/ATLAS