New moon western horizon shortly after sunset and before moonset. A lunation or synodic month is the average time from one new moon to the next. In the J2000.0 epoch, the average length of a lunation is 29.530588 days (or 29 days, 12 hours, 44 minutes, and 2.8 seconds). However, the length of any one synodic month can vary from 29.26 to 29.80 days due to the perturbing effects of the Sun's gravity on the Moon's eccentric orbit. In a lunar calendar, each month corresponds to a lunation. Each lunar cycle can be assigned a unique lunation number to identify it. The
June 1991 lunar eclipse June 1991 lunar eclipse A penumbral lunar eclipse took place on Thursday, June 27, 1991, the second of four lunar eclipses in 1991. The moon entered the Earth's penumbra for about 3 hours, and was difficult to see. This lunar eclipse is the predecessor of the Solar eclipse of July 11, 1991. This eclipse is a member of Saros series 110. The previous event occurred on June 15, 1973. The next event was on July 7, 2009. A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros). This lunar eclipse