For over two months, astronomers have been tracking 3I/ATLAS, a massive interstellar object currently hurtling through the solar system at staggering speed.
The unusual visitor is only the third interstellar object ever detected.
It follows the discovery of ‘Oumuamua in 2017 and 2I/Borisov in 2019.
Scientists generally believe 3I/ATLAS to be a comet.
However, new findings suggest the object is far stranger and much larger than anyone first thought.
Harvard astrophysicist Avi Loeb has spent years exploring whether some of these cosmic intruders could be artifacts of advanced extraterrestrial civilizations.
Loeb now suggests 3I/ATLAS may be tens of billions of tons in mass.
By studying its unusual trajectory, Loeb and his colleagues determined its “non-gravitational acceleration” was “smaller than 49 feet per day, squared.”
Combined with data on how much material the object is shedding, Loeb inferred that the “mass of 3I/ATLAS must be bigger than 33 billion tons.”
“Consequently, the diameter of its solid-density nucleus must be larger than [3.1 miles],” he wrote in a recent blog post.
That size would make 3I/ATLAS three to five orders of magnitude larger than either of the two previously discovered interstellar visitors.
The finding is a rare and puzzling result.
Loeb underscored just