Sunday 29 June 2014
In astronomy, new moon' is the first phase of the Moon, when it lies closest to the Sun in the sky as seen from the Earth. More precisely, it is the instant when the Moon and the Sun have the same ecliptical longitude. The Moon is not normally visible at this time except when it is seen in silhouette during a solar eclipse. See the article on phases of the Moon for further details. The original meaning of the phrase new moon, sometimes still used in non-astronomical contexts, was the first visible crescent of the Moon, after conjunction with the Sun. This takes place over the western horizon in a brief period between sunset and moonset, and therefore the precise time and even the date of the appearance of the new moon by this definition will be influenced by the geographical location of the observer. The astronomical new moon, sometimes known as the dark moon to avoid confusion, occurs by definition at the moment of conjunction in ecliptical longitude with the Sun, when the Moon is invisible from the Earth. This moment is unique and does not depend on location, and in certain circumstances it coincides with a solar eclipse. Source
