Image of 3I/ATLAS at a distance of 28.96 million kilometers, taken by the Tianwen-1 Mars orbiter of CNSA. (Credit: Cai Jinman & Zhang Wei, CNSA)
On October 3, 2025, the interstellar object 3I/ATLAS came within 29 million kilometers of Mars. The highest resolution images of 3I/ATLAS were obtained by the HiRISE camera onboard the Mars Reconnaissance Orbiter. This camera with a 50-centimeter aperture reached a spatial resolution of 30 kilometers per pixel, about 3 times better than the Hubble Space Telescope image from July 21, 2025 (accessible here).
Yesterday, the brilliant congresswoman Anna Paulina Lune tweeted the following message:
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This follows a DEFENSESCOOP news report titled “US government grapples with questions about interstellar object 3I/ATLAS amid shutdown”, accessible here.
While we are all waiting for the end of the U.S. government shutdown and the release of the HiRISE images of 3I/ATLAS, China National Space Administration (CNSA) released here images obtained on October 3, 2025 by the Tianwen-1 Mars Orbiter at a distance of 28.96 million kilometers from 3I/ATLAS.
The Tianwen-1 orbiter entered Mars orbit in February 2021. Its High-Resolution Imaging Camera (HiRIC), described here, employs a primary mirror diameter of 38.7 centimeters, with an inferior resolution relative to the 50-centimeter aperture of the HiRISE camera. The released HiRIC images show the nucleus and a surrounding coma with a diameter of several thousand kilometers. The CNSA researchers generated an animation of the trajectory of 3I/ATLAS in the Martian sky based on a series of 30-second images, available here.
Here’s hoping for better images from NASA’s HiRISE in the coming days.
ABOUT THE AUTHOR
Press enter or click to view image in full size(Image Credit: Chris Michel, National Academy of Sciences, 2023)
Avi Loeb is the head of the Galileo Project, founding director of Harvard University’s — Black Hole Initiative, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics, and the former chair of the astronomy department at Harvard University (2011–2020). He is a former member of the President’s Council of Advisors on Science and Technology and a former chair of the Board on Physics and Astronomy of the National Academies. He is the bestselling author of “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth” and a co-author of the textbook “Life in the Cosmos”, both published in 2021. The paperback edition of his new book, titled “Interstellar”, was published in August 2024.