What is a lunar eclipse? A lunar eclipse occurs when the Moon enters the Earth's shadow. In other words, when the Sun, Earth and Moon are in a straight line. The Moon will be full. However, lunar eclipses do not occur every time there is a full Moon. This is because the orbit of the Moon around the Earth is at an angle of about 5 degrees from the orbital plane of the Earth. Lunar eclipses may be partial eclipses or full eclipses. A partial eclipse occurs when the Moon only partially enters the Earth's shadow, and a full eclipse occurs when the Moon entirely enters the shadow. During a full eclipse, red light passing through the atmosphere of the Earth partially lights up the Moon, giving it a reddish appearance, so even though the Moon is entirely within the Earth's shadow it still remains visible.

Star Eclipse Guide During a lunar eclipse, stars may also be eclipsed. During the upcoming lunar eclipse, the Delta star of the "Futago" constellation will be eclipsed by the Moon as it is eclipsed by the Earth, and then the star will emerge from the opposite side of the Moon. This is called a stellar eclipse. The Moon takes about 30 days to complete one orbit around the Earth but usually when we watch the Moon we don't notice any movement in the position of the stars. During this eclipse however, it will be possible to appreciate the relative motion of the Moon with regard to the background stars. As the visible face of the Moon is large, lunar eclipses occur relatively frequently, but right in the middle of this eclipse a bright (magnitude 3.4) star will be eclipsed. This is very rare. Don't miss it!