Interstellar comet 3I/ATLAS surprises scientists with its chemistry
Interstellar visitor 3I/ATLAS, spotted throughout 2025, has a chemical mix that's unlike any comet from our solar system.
Using powerful telescopes, astronomers found it produces loads of methanol—about 40kg every second—which is much higher than usual for comets.
What makes 3I/ATLAS so unusual?
Besides the methanol spike (making up 8% of its vapor), the comet releases hydrogen cyanide and has a carbon dioxide-to-water ratio of 8:1—both rare finds.
Even more surprising, it's packed with nickel vapor with almost no iron detected, hinting at a chemical signature not seen in local comets.
When and how could you spot it?
3I/ATLAS reached its closest point to the Sun on October 29.
It looks like a faint reddish blur through telescopes from dark-sky spots.
Astronomy apps and observatory updates can help you track its path after perihelion.
Why does this matter?
These odd chemicals suggest complex reactions involving water and metals inside the comet—possibly offering clues about how organic molecules form in other star systems.
The findings challenge what we thought we knew about comets and where life's building blocks might come from.