Interstellar Comet 3I/ATLAS Brightens Rapidly Near Perihelion

• Interstellar comet 3I/ATLAS has shown a sharp increase in brightness as it passed behind the Sun, reaching perihelion on October 29 . Although hidden from Earth-based telescopes during this period, several spacecraft—including NOAA’s GOES-19 (CCOR-1) , NASA–ESA’s SOHO (LASCO C3) , and NASA’s PUNCH mission —successfully tracked its activity through coronagraph imagery.

Brightening and Observation

• The comet brightened from about magnitude 11 to magnitude 9 , consistent with increased dust and gas release as solar heating intensified near the Sun. Despite being invisible to the naked eye, it may soon be observable through small telescopes once it moves out of the Sun’s glare.

Scientific Significance

• 3I/ATLAS is only the third confirmed interstellar object detected passing through our Solar System. Continued monitoring as it re-emerges from solar conjunction will help scientists study its composition, outgassing behavior, and dust-to-gas ratios , offering valuable insights into material from beyond our solar neighborhood.

Exam-Oriented Facts:

• Comet: 3I/ATLAS (interstellar origin)

• Perihelion Date: 29 October 2025

• Observed By: GOES-19 (CCOR-1), SOHO (LASCO C3), NASA’s PUNCH

• Brightness: Increased from ~mag 11 to ~mag 9

• Significance: Provides data on interstellar materials and cometary behavior near the Sun