NASA Captures Unprecedented Data on Interstellar Comet 3I/ATLAS

Observations from over a dozen NASA missions provide new insights into the comet's composition and structure.

Mar. 21, 2026 at 7:18am

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The interstellar comet 3I/ATLAS, only the third such object ever detected passing through our solar system, was extensively observed by more than a dozen NASA science missions before it departed. This wealth of data, now available in NASA's public archives, is expected to fuel future discoveries about the nature of interstellar comets for decades to come.

Why it matters

Interstellar objects like 3I/ATLAS provide a rare opportunity for scientists to study the composition and structure of comets that originated outside our solar system. By combining data from multiple NASA missions, researchers were able to uncover unique characteristics of 3I/ATLAS that differ from typical comets, offering new insights into the diversity of these celestial visitors.

The details

NASA's TESS mission first spotted 3I/ATLAS in May 2025, well before its official discovery by the ATLAS survey telescope in July. This early detection allowed astronomers to better track the comet's trajectory. Researchers then combined data from MAVEN, Webb, and SPHEREx to reveal that 3I/ATLAS had different production rates of water, carbon dioxide, and carbon monoxide compared to comets native to our solar system.

  • The NASA-funded ATLAS survey telescope in Chile first discovered 3I/ATLAS on July 1, 2025.
  • NASA's TESS mission captured the comet on camera in May 2025, several months before its official discovery.
  • Observations of 3I/ATLAS by NASA's MAVEN, James Webb Space Telescope, and SPHEREx mission occurred in October 2025.

The players

3I/ATLAS

An interstellar comet, only the third such object ever detected passing through our solar system.

NASA

The U.S. National Aeronautics and Space Administration, which operates numerous science missions that observed 3I/ATLAS.

Kevin Murphy

The chief science data officer at NASA Headquarters.

Thomas Statler

The lead scientist for Solar System Small Bodies at NASA Headquarters, who coordinated the agency's observation campaign for 3I/ATLAS.

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What they’re saying

“NASA's scientific data archives are a gold mine of discoveries waiting to be made. The early observations of 3I/ATLAS from the TESS mission represent just one example of the exciting insights our open data can reveal.”

— Kevin Murphy, Chief Science Data Officer, NASA Headquarters

“Open science, as a set of principles, has been pushing us as research communities and NASA to make data more accessible. It's worked into the way we structure and establish standards for our data archives. That's what makes our data usable.”

— Thomas Statler, Lead Scientist for Solar System Small Bodies, NASA Headquarters

What’s next

As more powerful telescopes come online, scientists expect the discovery of interstellar objects passing through our solar system to become much more common. The wealth of data collected on 3I/ATLAS will provide an important context for understanding these rare celestial visitors for years to come.

The takeaway

NASA's commitment to open science and public data archives has enabled unprecedented insights into the nature of interstellar comet 3I/ATLAS, which could inform our understanding of these mysterious objects for decades. This highlights the value of making scientific data widely accessible to fuel future discoveries.