Recent ultraviolet (UV) images from the imaging ultraviolet spectrometer (IUVS) on NASA’s MAVEN (Mars Atmosphere and Volatile Evolution) orbiter have provided unique insights into the interstellar comet 3I/ATLAS, offering details about its chemical composition and the amount of water vapor released as it warms under the Sun. These findings will aid scientists in understanding the past, present, and future of 3I/ATLAS.
This ultraviolet image displays the coma of 3I/ATLAS as observed on October 9, 2025, by NASA’s MAVEN spacecraft utilizing its IUVS camera. The brightest pixel in the center marks the comet’s location, while the surrounding bright pixels show the presence of hydrogen atoms emanating from the comet. Image credit: NASA/Goddard/LASP/CU Boulder.
MAVEN captured images of 3I/ATLAS over a span of 10 days starting September 27, 2025, using IUVS cameras in two distinctive methods.
Initially, IUVS generated multiple images of the comet across several wavelengths, akin to using various filters on a single camera.
Subsequently, high-resolution UV images were obtained to identify the hydrogen emitted by 3I/ATLAS.
Analyzing these images together allows researchers to pinpoint various molecules and gain a deeper understanding of the comet’s makeup.
“The images gathered by MAVEN are truly astounding,” remarked Dr. Shannon Currie, MAVEN’s principal investigator.
“The detections we observe are significant, and we have merely begun our analysis journey.”
This annotated composite image highlights hydrogen atoms from three origins, including 3I/ATLAS (left), captured by NASA’s MAVEN orbiter on September 28, 2025, using an IUVS camera. The bright stripe on the right corresponds to hydrogen released from Mars, while the dark stripe in the center represents interplanetary hydrogen present in the solar system. Image credit: NASA/Goddard/LASP/CU Boulder.
The IUVS data also provides an estimated upper limit on the ratio of deuterium to normal hydrogen in comets, which is crucial for tracking their origin and evolution.
During the comet’s closest approach to Mars, Curry and his team utilized IUVS’s more sensitive channel to map various atoms and molecules, such as hydrogen and hydroxyls, within the comet’s coma.
Further examination of the comet’s chemical makeup could shed light on its origins and evolutionary journey.
“I experienced a rush of adrenaline when I saw what we had documented,” stated Dr. Justin Dahan, co-principal investigator of MAVEN and a member of the Atmospheric and Space Physics Laboratory at the University of Colorado Boulder.
“Every observation we make about this comet will enhance our understanding of interstellar objects.”
Source: www.sci.news
