WASHINGTON DC – During the Nov. 19 NASA news conference on Comet 3I/ATLAS, the NASA panelists likened the new observations to fans at a baseball game, each holding a camera and photographing the action from a different angle. Only by comparing and contrasting all these views will our most complete understanding of 3I/ATLAS emerge.

And the game’s not done yet. As the comet approaches its closest point to Earth (on Dec. 19), many more telescopes will take a bite at the cosmic apple. It won’t just be NASA and the world’s biggest observatories watching, but amateur astronomers, too.

For months, because of Comet 3I/ATLAS’s unusual trajectory and unprecedented size it ignited debates and theories as to what the object could be. A controversial theory put forward by Avi Loeb, a Harvard astrophysicist and his team is that the interstellar object might be some form of “alien technology.”

The release of photos captured by a fleet of NASA telescopes had been delayed due to the Federal government shutdown, helping to fuel some of these theories.

But during the news conference, NASA released new images and data collected during an intensive, solar system-wide observation campaign focused on Comet 3I/ATLAS, the third known interstellar object to pass through our solar system. The observations aim to understand how this comet differs from our own solar system’s comets, providing a unique window into the composition of other star systems.   

  • Discovery and Origin: The comet was discovered on July 1 by the NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System) telescope in Chile. It is classified as an interstellar object because its trajectory is an open path (hyperbolic), confirming it originated from outside our solar system.  

  • Mars Observations: The closest imagery was taken when the comet passed within 19 million miles of Mars.   

    • The Mars Reconnaissance Orbiter (MRO) captured some of the closest images.   

    • The MAVEN orbiter obtained ultraviolet images to help scientists understand its make-up.

    • The Perseverance rover also managed to get a faint glimpse from the Martian surface.   

  • Multiple NASA Assets: A dozen NASA missions, including both spacecraft and space telescopes, have been utilized:   

    • Hubble Space Telescope was used to estimate the size of the nucleus.   

    • The James Webb Telescope (JWST) and SPHEREx also captured imagery.Other missions like Psyche, Lucy, STEREO, and PUNCH have also contributed to the data collection.   

  • Path and Distance:

    • Comet 3I/ATLAS will make its closest pass to Earth around Friday, December 19, at a distance of 170 million miles (almost twice the distance from the Earth to the Sun).   It will continue its journey through the solar system, passing the orbit of Jupiter in the spring of 2026  

3I/ATLAS is the third known interstellar object to pass through our solar system. Twelve NASA assets have captured and processed imagery of the comet since it was first discovered on July 1, and several others will have opportunities to capture more images as the comet continues to pass through our solar system.

By observing the comet from so many locations, NASA has an opportunity to learn about the ways that 3I/ATLAS differs from our solar system’s home-grown comets and give scientists a new window into how the compositions of other systems may differ from our own.

Observations from Mars

The closest imagery of the comet was taken by NASA’s spacecraft at Mars. Earlier this fall, 3I/ATLAS passed by Mars from a distance of 19 million miles, where it was observed by three NASA spacecraft. The Mars Reconnaissance Orbiter (MRO) captured one of the closest images of the comet, while the MAVEN (Mars Atmosphere and Volatile EvolutioN) orbiter obtained ultraviolet images that will help scientists understand the comet’s make-up. Meanwhile, the Perseverance rover grabbed a faint glimpse from the surface of Mars.

View pictures at NASA

The NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System) telescope in Chile discovered 3I/ATLAS on July 1. Later that month it was viewed by NASA’s Hubble Space Telescope. In August, both NASA’s James Webb Telescope and SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer) captured imagery.

Comet 3I/ATLAS will fly closest to Earth about Friday, Dec. 19, at 170 million miles, which is almost twice the distance between the Earth and Sun. NASA spacecraft will continue to observe the comet as it makes its journey through the solar system, passing the orbit of Jupiter in spring 2026.

For more information on NASA’s comet 3I/ATLAS observations, visit:

https://go.nasa.gov/3I-ATLAS