NASA looks for the origins of interstellar comet 3I/ATLAS | Space photo of the day for June 24, 2026

Researchers using JWST are finding clues about comet 3I/ATLAS' origins. (Image credit: NASA, ESA, CSA, STScI, Martin Cordiner (CUA, NASA-GSFC); Image Processing: Alyssa Pagan (STScI))

NASA's James Webb Space Telescope is finding clues that are leading scientists closer to understanding the origins of the interstellar comet 3I/ATLAS.

What is it?

Comet 3I/ATLAS captured the world's attention when it was discovered nearly a year ago on July 1, 2025. The comet was first spotted by the Asteroid Terrestrial-impact Last Alert System (ATLAS), and is only the third interstellar object every discovered.

The comet swooped through our solar system, passing by Earth at a far (and safe) distance on its tour of our cosmic neighborhood. It is on a long trajectory that will take it out of our solar system, never to return.

In observations from the James Webb Space Telescope, scientists were able to look in the direction the comet as it began moving away from the sun in December of last year. While in close proximity to our star, the sun's heat warmed the comet, making it extra bright and easy to observe.

With this view, astronomers were able to calculate some of the ratios of the chemicals present in the comet. This further highlighted that the object is from out of our solar system, as they found ratios of carbon and heavy hydrogen not found in comets in our solar system.

Researchers described their results in a new paper published June 22 in the journal Nature.

A chart exploring the new findings about 3I/ATLAS.

This graph shows some of the differences between 3I/ATLAS and comets found in our own solar system. (Image credit: NASA, ESA, CSA, Martin Cordiner (CUA, NASA-GSFC), Leah Hustak (STScI))

Why is it incredible?

Being only the third interstellar object ever found, people were excited about 3I/ATLAS. They were so excited, in fact, that conspiracies about the object sprouted up quickly. Due to it being from outside of our solar system, some claimed that the comet could be some sort of alien spaceship, similar to the initial suspicions about the interstellar object 'Oumuamua found years earlier.

But with new information coming in from space telescopes, and astronomers eager to understand this object better, these clues are leading us closer and closer to the true origins of this strange comet.

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Chelsea Gohd
Content Manager

Chelsea Gohd served as a Senior Writer for Space.com from 2018 to 2022 before returning in 2026, covering everything from climate change to planetary science and human spaceflight in both articles and on-camera in videos. With a M.S. in Biology, Chelsea has written and worked for institutions including NASA JPL, the American Museum of Natural History, Scientific American, Discover Magazine Blog, Astronomy Magazine, and Live Science. When not writing, editing or filming something space-y, Gohd is writing music and performing as Foxanne, even launching a song to space in 2021 with Inspiration4. You can follow her online @chelsea.gohd and @foxanne.music