determine the phase of the moon in which a lunar eclipse can occur.

A lunar eclipse can occur only during the full moon phase, when the Sun, Earth, and Moon line up so that Earth’s shadow falls on the Moon.

Quick Scoop

• A lunar eclipse happens when Earth comes directly between the Sun and the Moon.

• This alignment is possible only at full Moon, because then the Moon is opposite the Sun in the sky, behind Earth from the Sun’s point of view.

• Even though there is a full Moon every month, a lunar eclipse does not happen every month because the Moon’s orbit is slightly tilted, so most full Moons miss Earth’s shadow.

In short: if it’s not a full Moon, it cannot be a lunar eclipse.

TL;DR: A lunar eclipse can occur only at full moon, when the Earth’s shadow can fall on the Moon.

Information gathered from public forums or data available on the internet and portrayed here.