The Moon phase for June 6th, 1944 is the Full Moon phase. In this phase, the moon is 100% illuminated when seen from Earth (hence the name Full Moon).

The Full Moon happens when the moon is on the opposite side of the Earth from the Sun. The sunlight fully illuminated the moon, and this is what we call being "full". The moon will be visible throughout the night sky as it rises at sunset in the east, transits the meridian at midnight, before setting at sunrise in the west.

The specific point at which the Full Moon occurs can be measured down to a fraction of a second. The time that passes between full moons is called the Synodic month and is 29.530587981 days long.

Fun fact: lunar eclipses can only happen within a few days of the Full Moon, but they don't happen for every Full Moon because the moon's orbit has a 5.1° tilt around the Earth compared to Earth's orbit around the Sun. Only when the intersection of these two orbits is pointing towards the centre of the Moon do we get a lunar eclipse.