During totality, the Earth’s shadow covers the entire face of the Moon and can even give the lunar orb a brown-reddish hue.
During a partial eclipse, only a fraction of the Full Moon’s face enters the planet’s shadow.
Ms Byrd said: “In a penumbral lunar eclipse, only the more diffuse outer shadow of Earth – the penumbra – falls on the Moon’s face.
“This third kind of lunar eclipse is much more subtle, and much more difficult to observe, than either a total or partial eclipse of the Moon.
“There is never a dark bite taken out of the Moon, as in a partial eclipse.”