"If you want to catch the comet, your best chance is over the next week or so."
Comet C/2025 R3 (PanSTARRS), a long-period comet discovered in September 2025 by the Pan-STARRS survey in Hawaii, is approaching perihelion. The comet is currently visible in the morning sky for Northern Hemisphere observers and will transition to the evening sky for Southern Hemisphere viewers later in April and May. The comet has an estimated orbital period of approximately 170,000 years.
Discovery and Classification
The comet was discovered in September 2025 by the Pan-STARRS survey in Hawaii. It is classified as a long-period comet originating from the Oort Cloud, a distant shell of icy objects at the edge of the solar system. Its estimated orbital period is roughly 170,000 years.
Brightness and Visibility Timeline
Current and Projected Brightness
Observations in early April placed Comet PanSTARRS at approximately magnitude +6, which is near the threshold of naked-eye visibility under very dark sky conditions. Light-curve data from the Comet Observation database suggests the comet could brighten to between magnitude +4 and +3 in the weeks surrounding perihelion. Comet brightness is inherently unpredictable, and actual visibility will depend on the comet's behavior as it approaches the sun. The comet is expected to be visible with binoculars and telescopes.
Recent Observations (Late March)
On March 26, the comet was observed at approximately magnitude 8, displaying a long tail with several visible disconnection events.
Orbital Milestones
- Perihelion (Closest Approach to Sun): April 19-20, 2025. The comet will pass within 47.4 million miles (76.3 million km) of the sun. This proximity can increase the comet's activity and brightness as ice sublimates into gas.
- Closest Approach to Earth: April 27, 2025. The comet will be approximately 44 million miles (70.8 million km) from Earth.
Viewing Information
Northern Hemisphere
Optimal Viewing Period: The recommended observation window for Northern Hemisphere observers is April 10-20, 2025. The best viewing opportunities are anticipated between April 13 and April 15.
Timing: The comet rises approximately at 3:40 A.M. local daylight time. It becomes visible about one hour later, reaching an altitude of 10° in the eastern sky around 4:45 A.M. local daylight time. Optimal viewing is approximately 90 minutes before sunrise. A clear, unobstructed eastern horizon is necessary for observation.
Location: The comet is located near the western side of the Great Square of Pegasus, positioned between the stars Alpha (Markab) and Beta (Scheat) Pegasi. From Markab, the comet can be located by shifting a telescope 5° north-northwest.
Path: From April 13-19, the comet will travel across the bottom of the Great Square of Pegasus asterism, moving from near Markab to near Algenib before entering the constellation Pisces.
Challenges: As the comet brightens, its visibility from the Northern Hemisphere will diminish as it moves closer to the sun in the sky, resulting in lower altitude above the horizon and increased competition with twilight. By the end of April, it will no longer be visible from the Northern Hemisphere.
Southern Hemisphere
Southern Hemisphere observers will have better viewing opportunities later in April and into May. During this period, the comet will move away from the sun in southern skies.
Timing: The comet will be visible in the western sky just after sunset. It is best observed within one hour after sunset, low on the horizon.
Viewing Regions: Recommended locations include New Zealand, Australia, South Africa, and the Pacific.
Appearance: The comet appears as a blue-green orb with a coma (gas cloud) and a fuzzy tail. It is not visible to the naked eye and requires binoculars, a telescope, or a camera for observation.
Notable Alignments
- April 14: The comet will appear near a 12% illuminated waning crescent moon and the planet Mercury.
- April 17: A new moon will provide dark skies, which could improve viewing conditions leading up to perihelion.
- April 18: The comet will pass within approximately 2 degrees of the edge-on spiral galaxy NGC 7814.
- April 19: The comet will exit the Great Square of Pegasus region, appearing about 2 degrees from the star Algenib.
Observing Recommendations
- Equipment: 10x50 binoculars are recommended for optimal viewing. Tripod-mounted cameras with 200-400mm lenses, ISO settings between 1600-6400, and short exposures in RAW format are suggested for photographic documentation.
- Guidance: Planetarium software or stargazing applications can be used to locate the comet's precise position relative to background stars.
Expert Statement
"You will need to get up early, a couple of hours before sunrise, and have a good, low, eastern horizon."
— Nick James, head of the comet section at the British Astronomical Association
Trajectory and Future Visibility
According to astronomer Josh Aoraki, the comet's trajectory is difficult to predict because mass loss as it passes the sun can alter its path. It may return as predicted or be ejected from the solar system. The comet will remain visible for approximately two weeks in the Southern Hemisphere before fading from view.