The moon was likely so bright last night because it was a supermoon.
What is a Supermoon?
A supermoon occurs when two astronomical events coincide:
- Perigee: The moon reaches the point in its orbit where it's closest to Earth.
- Full Moon: The moon is in its full phase.
When both of these events happen at the same time, as reference material suggests occurs, the moon appears significantly brighter and larger in the sky than a regular full moon. The reference material mentions the appearance change is up to 30% brighter and 14% larger.
| Feature | Supermoon | Regular Full Moon |
|---|---|---|
| Brightness | Appears brighter (up to 30% brighter) | Appears less bright |
| Size | Appears larger (up to 14% larger) | Appears smaller |
| Cause | Perigee and full moon occurring together | Full moon occurring at a further distance |
Therefore, if last night featured a full moon at the same time as the moon's closest approach to Earth (perigee), this created a supermoon and made the moon appear remarkably bright.
