Story perspectives

Ancient Comet 3I/ATLAS Emitting Water Vapor Surprises Scientists

10/13/2025

Summary

Story summary

The interstellar comet 3I/ATLAS emits water vapor at 88 pounds per second, according to NASA's Neil Gehrels Swift space telescope.
The emission occurs three astronomical units from the Sun, challenging typical comet behavior.
The comet has a carbon dioxide to water ratio higher than local comets.
Astronomers believe 3I/ATLAS originated from Milky Way's center and is billions of years old.
As it becomes visible in late November, scientists expect insights.

1 of 1

Story summary

The interstellar comet 3I/ATLAS emits water vapor at 88 pounds per second, according to NASA's Neil Gehrels Swift space telescope.
The emission occurs three astronomical units from the Sun, challenging typical comet behavior.
The comet has a carbon dioxide to water ratio higher than local comets.
Astronomers believe 3I/ATLAS originated from Milky Way's center and is billions of years old.
As it becomes visible in late November, scientists expect insights.