Moon illusion visible over southern and eastern Norway

A moon illusion that makes the moon appear larger than usual was visible across southern and eastern Norway on the night leading into Thursday, Dagbladet reports.

The phenomenon is an optical illusion. According to NASA, photographs show the moon has the same width near the horizon as when it is high in the sky, but the eyes and brain perceive it as much larger when it is low.

Researchers have yet to confirm why this occurs.

Southern Norway had the best conditions to observe the phenomenon, said Rune Aae, who has taught astronomy for over 20 years at colleges and universities. Further north, such as in Tromsø, the moon was not visible because it did not rise above the horizon.