20.12.2025
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.
Quelle: NASA
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NASA’s PUNCH Spies Comet Lemmon
In late 2025, as comet Lemmon (C/2025 A6) swept past the Sun and brightened in Earth’s night skies, NASA’s Earth-orbiting PUNCH (Polarimeter to Unify the Corona and Heliosphere) mission was watching the comet blaze through its field of view, providing a natural tracer of the Sun’s effects across the inner solar system.
Discovered in January 2025 using a NASA-funded survey telescope on Mount Lemmon in Arizona, comet Lemmon first appeared in PUNCH’s view in October.
This movie, made from PUNCH images taken from Oct. 22 to Nov. 12, shows the comet’s movement against background stars and shows changes in the comet’s tail. Variations in the solar wind — a stream of particles that flows out from the Sun — affects the comet’s tail, with occasional solar outbursts causing more dramatic fluctuations in the tail. Twice, on Nov. 1 and Nov. 4, the comet’s tail appears to waver and break in response to solar activity. The tail shortens briefly but then regrows over the following days.
Comet Lemmon continues to be visible in PUNCH images, though it is now getting fainter with each passing day. Mission scientists expect it to leave PUNCH’s view by mid-January 2026 as it moves farther away from both the Sun and Earth.
Southwest Research Institute, based in San Antonio, leads the PUNCH mission and operates the mission’s four spacecraft from its facilities in Boulder, Colorado. The mission is managed by Space Science Mission Operations at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, for the Science Mission Directorate at the agency’s headquarters in Washington.
Quelle: NASA