A "supermoon", the last such occurrence in 2025, will be visible in the sky on December 5. It is the third supermoon this year and will be the second largest in apparent size.
A supermoon, known in astronomy as a perigee full moon, occurs when the moon reaches its full phase near the point in its orbit closest to Earth (perigee). This makes it appear larger and brighter than a typical full moon. The moon's orbit is elliptical, with perigee about 360,000 km from Earth and apogee (the farthest point) about 400,000 km away.
Viewing details
The moon will be at its fullest around 07:14 local time on December 5, but since this is after sunrise, the best time for viewing will be the evening of December 4. As the moon rises near the horizon, it may appear especially large due to the "moon illusion" effect.
No special equipment is needed to observe the supermoon. A pair of 7x to 12x binoculars can reveal lunar maria and major craters, while a telescope allows for more detailed viewing. For photography, using a phone's professional or "moon" mode with a low ISO (around 100) and fast shutter speed (1/125s to 1/500s), along with a tripod, can improve results.
Ideal spots include dark-sky locations away from city lights, such as rural areas, hilltops, or open waterfronts. Urban observers can try rooftops or parks with a clear view to the east.
This supermoon is the last in a series of three that have occurred in recent months. The next supermoons are expected in 2026.
Other celestial events in December
• December 7: Jupiter will appear near the moon in the evening sky.
• December 14: The Geminid meteor shower peaks.
• December 31: A lunar occultation of the Pleiades star cluster will be visible.
Author | Feng Huiting
Photo | Nanfang Plus
Editor | Wei Shen, James Campion, Shen He
