Solar eclipses are only possible during the new Moon phase, when the Moon is directly between the Sun and Earth. An observer on Earth may see part or all of the Sun blocked, depending on the positions of the objects. It is more common to see a partial solar eclipse, when the Moon covers just a part of the Sun's disk. A total solar eclipse is less common and only happens when the Moon, the Sun, and Earth align perfectly and the Sun’s light is completely blocked by the Moon.