Lunar day around the Sun at the same time, the Moon must travel further to return to the same phase. On average, this synodic period lasts 29 days, 12 hours, 44 minutes, and 3 seconds. This is the mean figure since the speed of the Earth–Moon system around the Sun varies slightly during a year due to the eccentricity of its elliptical orbit, variances in orbital velocity, and a number of other periodic and evolving variations about its observed, relative, mean values, which are influenced by the gravitational perturbations of the Sun and other bodies in the Solar System. As a result,
April 2015 lunar eclipse April 2015 lunar eclipse A total lunar eclipse took place on 4 April 2015. It is the former of two total lunar eclipses in 2015, and the third in a "tetrad" (four total lunar eclipses in series). Other eclipses in the tetrad are those of 15 April 2014, 8 October 2014, and 28 September 2015. This is the 30th member of Lunar Saros 132, and the first total eclipse. The previous event was the March 1997 lunar eclipse, being slightly partial. Totality lasted only 4 minutes and 44 seconds, making it the shortest lunar totality in almost five centuries since