NASA’s Parker Solar Probe Observes Interstellar Comet 3I/ATLAS

NASA’s Parker Solar Probe observed interstellar comet 3I/ATLAS from Oct. 18 to Nov. 5, 2025, with its WISPR (Wide-Field Imager for Solar Probe) instrument. The spacecraft snapped around 10 images of the comet per day. During this period, Parker Solar Probe was speeding away from the Sun following its 25th solar flyby on Sept. 15. 

In these initial images — which still need to go through final calibration and processing — the comet can be seen heading behind the Sun from Parker’s point of view. At the time, the comet was near its closest point to the Sun, at a distance of about 130 million miles, placing it just outside the orbit of Mars. The images offer a valuable look at the comet over a period when it couldn’t be seen from Earth because it appeared too close to the Sun from Earth’s perspective. 

The WISPR team is continuing to process the data to remove stray sunlight and compensate for exposure times, which differed between the images, causing the comet to appear as if it changed brightness. The final images will ultimately help scientists better study this interstellar visitor.  

Comet 3I/ATLAS was discovered by the NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System) survey telescope in Rio Hurtado, Chile, in July. It is the third known object originating from outside our solar system discovered passing through our solar neighborhood. Comet 3I/ATLAS was also seen by other NASA heliophysics missions including PUNCH, STEREO, and SOHO. 

By Mara Johnson-Groh 

NASA’s Goddard Space Flight Center, Greenbelt, Md. 

December 19, 2025