Basics
- Definition: A supermoon occurs when a full moon or new moon coincides with the moon’s closest approach to Earth (perigee) in its elliptical orbit.
- Perigee distance variation: The moon’s orbit is not a perfect circle; distance from Earth varies by ~50,000 km.
- Visual effect: Full moon at perigee appears ~14% larger and ~30% brighter than at apogee (farthest point).
Relevance :
- GS3 – Science & Technology / Space
- Astronomy: Moon’s orbit, perigee/apogee, tidal effects.
- Scientific observation opportunities, satellite impact, tidal studies.
- GS1 – Geography (Physical)
- Earth-moon interactions affecting tides, coastal flooding, and oceanography.
Recent Occurrences
- Supermoon visible on October 7, 2025.
- Two more supermoons expected in November and December 2025.
Origin and Popularisation
- Term “supermoon” popularised by astrologer Richard Nolle in the 1970s.
- Widely adopted by astronomers and media to describe visually striking lunar events.
Astronomical Significance
- Brightness perception: Subtle size difference may not be easily noticed with the naked eye; brightness and low-horizon view make it appear vivid.
- Tidal impact:
- Causes perigean spring tides — tides slightly higher/lower than usual.
- Results from moon’s stronger gravitational pull aligning with the sun.
- Can exacerbate coastal flooding if coinciding with storm surges.
Cultural and Scientific Relevance
- Cultural impact:
- Supermoons have inspired folklore, mythology, and spiritual observances across civilizations.
- Scientific opportunities:
- Enables astronomers to observe lunar surface details more clearly.
- Facilitates study of tidal effects and oceanographic impacts.
- Offers photography opportunities due to enhanced brightness and apparent size.
Key Takeaways
- Supermoon = astronomical + cultural phenomenon.
- Visual impact is enhanced near horizon; effect on tides is modest but not negligible.
- Highlights the interaction between celestial mechanics (moon’s orbit) and Earth phenomena (tides).
- Serves as a reminder of how orbital dynamics influence everyday life and culture.
