SouthernWorldwide.com – An interstellar comet that passed by Earth last year might be the oldest and coldest object ever observed in our solar system, according to astronomers.
The comet, designated 3I/ATLAS, is only the third known object from outside our solar system to be detected by humanity. Its remarkable brightness has provided scientists with a unique chance to study an object originating from another part of the galaxy.
The discovery of the comet in July of last year generated significant online buzz. A prominent Harvard researcher even speculated it could be an alien spacecraft, a theory later dismissed by NASA.
Recent observations from the world’s most powerful telescopes are now shedding more light on this extraordinary comet.
A new study, published in the journal Nature, suggests that 3I/ATLAS could be as old as 12 million years. For context, our solar system is estimated to have formed approximately 4.5 billion years ago.
Martin Cordiner, lead author of the study and a researcher at NASA’s Goddard Space Flight Center, commented to AFP that the comet “maybe it’s the oldest object to have been observed in our solar system.”
However, Cordiner also noted that there might be “edge-case scenarios” that could explain the comet’s unusual chemical composition through alternative means.
The latest research is based on the analysis of isotopes, which are different forms of chemical elements, detected by the James Webb Space Telescope and the ALMA observatory in Chile.
These measurements indicate that the comet possesses “an elemental composition unlike any solar system body,” as stated in the study.
Possible relic from “cosmic noon”
Compared to comets originating within our solar system, 3I/ATLAS contains ten times more deuterium, a heavier form of hydrogen often found in heavy water, according to the study.
“That high abundance of heavy water can only really happen, according to our understanding of astrochemistry, in a very cold environment,” Cordiner explained.
This suggests that the comet is likely among the coldest objects ever observed in our solar system, with isotopic evidence pointing to its formation in an environment as low as minus 243 degrees Celsius.
The exact origin of this comet within the Milky Way remains unknown.
However, it is believed that these interstellar objects form in a manner similar to comets within our Solar System – they are ejected during the violent formation of a new planet.
Unbound to any star, 3I/ATLAS has likely traveled on “vast unimaginable trajectories around our galaxy” for billions of years, Cordiner stated.
Scientists also observed a notable lack of chemical enrichment on the comet, hinting that it may have formed relatively close to newly forming stars.
It could potentially be a “relic” from a period known as “cosmic noon,” when numerous stars were being born approximately 10 billion years ago, Cordiner suggested.
The two previous interstellar objects detected, 1I/’Oumuamua in 2017 and 2I/Borisov in 2019, were not bright enough to allow for the collection of isotopic data.
NASA has released several images of 3I/ATLAS. One image from November showed the comet traversing space at a distance of about 180 million miles from Earth.
In October of the previous year, images captured by two Mars orbiters revealed the comet as a bright, fuzzy white dot against a backdrop of stars, approximately 18,641,135 miles away from Mars.
The month before that, an image depicted the growing tail of 3I/ATLAS as it streaked across our solar system.
Avi Loeb, a Harvard professor who previously generated controversy by proposing that ‘Oumuamua might be an alien spacecraft, made similar suggestions regarding 3I/ATLAS.
“We should put all possibilities on the table that it’s a rock, a comet, or something else until we get the evidence, the data that will tell us what it is,” Loeb stated in an interview with CBS Boston.
However, NASA has refuted the possibility of extraterrestrial life. The Search for Extraterrestrial Intelligence Institute (SETI) announced last month that it had found “no evidence of extraterrestrial technology” on the comet.
“Just the beginning”
Several astronomers who have studied 3I/ATLAS, but were not part of the recent research, praised the groundbreaking findings.
“Until these measurements we could only really dream about” obtaining such information for an interstellar object, Darryl Seligman of Michigan State University told AFP.
He cautioned that the comet’s age is still uncertain, but added that it is “a safe bet that it’s older than anything that formed in the solar system.”
Astronomer Peter Veres, who was involved in identifying the comet at the International Astronomical Union’s Minor Planet Center, described the research as “exciting.”
“The comet is now leaving the solar system and will never return, so future observations will become increasingly difficult,” he informed AFP.
Despite this, astronomers anticipate detecting many more interstellar objects in the coming years, particularly with the advent of the new Vera C. Rubin Observatory in Chile.
“This is just the beginning of an exciting new field, we’ve got a lot more to learn about these things — and what they can tell us about our galaxy,” Cordiner concluded.
