Orbit of the Moon orbit of the Moon is distinctly elliptical, with an average eccentricity of 0.0549. The non-circular form of the lunar orbit causes variations in the Moon's angular speed and apparent size as it moves towards and away from an observer on Earth. The mean angular movement relative to an imaginary observer at the Earth-Moon barycentre is ° per day to the east (Julian day 2000). The Moon's elongation is its angular distance east of the Sun at any time. At new moon, it is zero and the Moon is said to be in conjunction. At full moon, the elongation is 180°
Equinox a larger antenna has a narrower beam-width and hence experiences shorter duration "Sun outage" windows.) Equinoxes occur on any planet with a tilted rotational axis. A dramatic example is Saturn, where the equinox places its ring system edge-on facing the Sun. As a result, they are visible only as a thin line when seen from Earth. When seen from above – a view seen during an equinox for the first time from the "Cassini" space probe in 2009 – they receive very little sunshine, indeed more planetshine than light from the Sun. This phenomenon occurs once every 14.7 years on