When and how to watch the 'great comet of 2026'
What's the story
Comet C/2025 R3 (Pan-STARRS) is an icy comet discovered in September 2025 by the Pan-STARRS survey telescope in Hawaii. Astronomers are calling it a potential "great comet of 2026" because it might become bright enough to see without optical aid later this year. The comet is expected to reach its closest point to the Sun (perihelion) around April 20, a phase when comets often brighten dramatically due to solar heating.
Trajectory details
C/2025 R3's journey and visibility
Currently, C/2025 R3 is around 216 million miles away from Earth and moving inward. It follows an elongated orbit around the Sun and will reach its closest point to the Sun around April 20. The celestial body will make its closest approach to Earth around April 27, 2026, passing at a safe distance of roughly 44 million miles. Observers in the Southern Hemisphere could have a particularly good view as sunlight scattering through its tail could enhance visibility.
Viewing tips
Optimal viewing window for C/2025 R3
The best time to observe the comet is likely on the evening of April 17, 2026. A new moon will make faint objects easier to see. The comet's brightness will increase significantly as it nears perihelion on April 20, and closest approach to Earth a week later on April 27. Timing is crucial to avoid sunlight obscuring the comet in skies.
Brightness predictions
Uncertainty surrounds C/2025 R3's brightness
Astronomers are unsure how bright this comet may get. Some estimates suggest it could reach a magnitude of 8, requiring binoculars to see. Others predict a much brighter magnitude of 2.5, making it clearly visible without any aid. Forward scattering may temporarily enhance brightness when the Sun aligns properly, creating an impressive celestial display as its tail glows brightly during the solar heating process.
Astronomical interest
C/2025 R3's significance and potential impact
The significance of C/2025 R3 lies in its potential to be a bright naked-eye comet, something that is quite rare. The 2025-26 period has already seen several smaller comets, but none have been spectacular. If predictions are correct, the "great comet of 2026" could be one of the most memorable celestial sights in years, sparking public interest in astronomy and space exploration worldwide.