MAVEN sees 3I/ATLAS halo

This image shows the halo of gas and dust, or coma, surrounding comet 3I/ATLAS, the third interstellar object ever detected by astronomers as it passes through our solar system. The image was taken on Oct. 9, 2025, by an instrument onboard NASA's MAVEN spacecraft, which has been studying Mars from its orbit since 2014. The instrument, the Imaging Ultraviolet Spectrograph, takes pictures in the ultraviolet part of the spectrum to reveal the chemical composition of objects. The center of the image has the brightest pixel, indicating where the comet is. The next brightest shades in the image indicate areas where the instrument detected atoms of hydrogen coming from the comet. This hydrogen is released when sunlight heats the comet, causing its water ice to turn directly into vapor. Once released into space, the water molecules break apart into oxygen and hydrogen atoms.