Stacked images of 3I/ATLAS from STEREO-A

This image shows the 3I/ATLAS interstellar comet as a bright, fuzzy orb in the center. Traveling through our solar system at 130,000 miles (209,000 kilometers) per hour, 3I/ATLAS was made visible by using a series of colorized stacked images from Sept. 11-25, using the Heliocentric Imager-1 (H1) instrument, a visible-light imager on the STEREO-A (Solar Terrestrial Relations Observatory) spacecraft. The colorization was applied to differentiate the image from other observing spacecraft images.