Blue moon - level 2
There was a full moon on the 2nd of July and on the 31st of July. According to modern folklore, when there are two full moons in a month, the second one is blue.
However, this is not exactly true. Blue moons can happen, but there must be a volcanic eruption. Back in 1883, people saw blue moons almost every night after the Indonesian volcano Krakatoa exploded. Some of the volcanic ash worked as a blue filter.
On the other hand, the moon can also get red when it is low in the sky.
Difficult words: folklore (the traditional stories of an area or country), ash (very small dust), on the other hand (however).