Understanding Blue Moons

What is the modern definition of a Blue Moon?

• The second full moon in a calendar month.

• A rare astronomical event involving the Moon.

• A full moon that occurs during a lunar eclipse.

• The Moon appears blue in color.

How did the meaning of 'Blue Moon' change over time?

• It always referred to a second full moon in a month.

• It originally referred to a rare event and now has an astronomical meaning.

• It was originally a term for a lunar eclipse.

• It has always meant the Moon appears blue.

What natural event can cause the Moon to appear blue?

• A volcanic eruption

• A solar eclipse

• A lunar eclipse

• A meteor shower

What size of particles in the atmosphere can make the Moon appear blue?

• 100 microns wide

• 10 microns wide

• 1 micron wide

• 0.1 micron wide

Why does the Moon often appear red when it is low in the sky?

• Because of volcanic ash in the atmosphere

• Due to the scattering of blue light by aerosols

• Due to the reflection of sunlight

• Because of a lunar eclipse