- NASA shared images of comet 3I/ATLAS, the third confirmed interstellar object in our Solar System
- Twelve spacecraft, including Mars rovers and solar probes, have captured images since its July 1 discovery
- Mars orbiters and rovers provided the closest images, with Mars Reconnaissance Orbiter imaging on Oct 2
NASA has shared highly-anticipated images of 3I/ATLAS, which is the third confirmed object to enter our Solar System from interstellar space, after 'Oumuamua (2017) and 2I/Borisov (2019). The comet's unusual trajectory sparked online rumours of "alien technology", but all eyes were on NASA to share details with the world.
Hence, NASA pointed virtually every spacecraft that could see the comet, turning the inner Solar System into a giant observatory. However, the images were delayed by the six-week US government shutdown as public releases were halted.
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The space agency noted that 12 assets captured and processed images of the comet since its discovery on July 1. As the comet continues to pass through our solar system, several other space probes still have a chance to observe the space object from new angles.
The space agencies got a rare, probably once-in-a-lifetime opportunity, with 3I/ATLAS offering a rare chance to study material that has travelled billions of kilometres because it originates from another star system.
Perseverance and MRO's observation from Mars
As per NASA, the closest imagery of the comet was taken by a spacecraft at the Red Planet. Perseverance rover's Mastcam-Z captured an image on Oct 4, MAVEN (Mars Atmosphere and Volatile EvolutioN) orbiter obtained ultraviolet images on Oct 9, and the High Resolution Imaging Science Experiment (HiRISE) camera aboard Mars Reconnaissance Orbiter captured it on Oct 2 at around 19 million miles from Mars.
This image was taken by HiRISE camera aboard NASA's Mars Reconnaissance Orbiter on October 2.
Photo Credit: NASA/JPL-Caltech/University of Arizona
This image was taken on Sept 28 by an instrument on MAVEN spacecraft.
Photo Credit: NASA/Goddard/LASP/CU Boulder
Comet's observation from the Sun
The object was also captured by some solar probes. NASA's STEREO (Solar Terrestrial Relations Observatory) captured its images from Sept 11 to Oct 2, and the ESA (European Space Agency) and NASA mission SOHO (Solar and Heliospheric Observatory) observed the comet from Oct. 15 to 26.
Solar-observing fleet - STEREO-A, SOHO and the PUNCH (Polarimeter to Unify the Corona and Heliosphere) imager recorded its motion from September 28 to October 10, when the comet was 231-235 million miles from Earth.
What did asteroid explorers find?
Some deep-space probes got the opportunity of observing the celestial celebrity with Lucy's L'LORRI imager (Sept 16) and the Psyche spacecraft's multispectral camera (Sept 8-9) added high-resolution views from 33-240 million miles.
Psyche mission acquired four observations of interstellar comet 31/ATLAS over the course of eight hours on Sept 8 and 9.
Photo Credit: NASA/JPL-Caltech/ASU
The comet, circled in the center, as seen by the L'LORRI panchromatic, or black-and-white, imager on NASA's Lucy spacecraft taken on Sept 16.
Photo Credit: NASA/Goddard/SwRI/JHU-APL
A diagram showing Lucy spacecraft on the opposite side of the Sun from Earth, with comet and Mars positioned between the spacecraft and the Sun.
Photo Credit: Credit: NASA/Goddard/SwRI
The James Webb Space Telescope (JWST) and SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer) had observed the comet in August. Hubble had also observed it.
Webb's Near-Infrared Spectrograph instrument is planned to observe the comet again in December, and scientists believe that it will provide the most detailed composition data yet.
The comet's speed is 30,000 mph, which is faster than any known Solar System comet, and it is rich in carbon dioxide and water ice. A surprisingly strong nickel signal was also detected, similar to 2I/Borisov.
Scientists are still uncertain about the size, and it is believed to range from a few hundred metres to a few kilometres, obscured by dust. The object brightened dramatically near perihelion on Oct 29 and showed a faint tail in visible-light images.
This image combines observations that PUNCH mission captured between Sept 20 and Oct 3, 2025.
Photo Credit: NASA/Southwest Research Institute
Close approach to Earth
According to NASA, comet 3I/ATLAS will fly closest to Earth on December 19.
It will be at 170 million miles, almost twice the distance between the Earth and the Sun.
