The NASA/ESA/CSA James Webb Space Telescope observed 3I/ATLAS on December 15-16 and again on December 27, 2025, when the comet was approximately 330 million and 380 million kilometers from the Sun, respectively. Using its Mid-Infrared Instrument, Webb captured the first direct detection of methane gas from any interstellar visitor.

3I/ATLAS was described as the third confirmed interstellar object after ʻOumuamua and 2I/Borisov, but the script says it did not behave like either of them. It passed within about 28 million kilometers of Mars on October 3,

A NASA probe that had a close encounter with a strange object from another solar system has been declared dead and scientists still do not know what happened.