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
Dundrod Circuit the 2017 Ulster Grand Prix. The race record for the Dundrod Circuit is an average speed of set by Bruce Anstey during the 2017 Ulster Grand Prix. The lap record for the RAC Tourist Trophy on the Dundrod Circuit is 4 minutes and 42 seconds at an average speed of 94.67 mph (152.3582 km/h) held by Mike Hawthorn driving a Jaguar D-Type set during the 1955 RAC Tourist Trophy. The race record for the RAC Tourist Trophy on the Dundrod Circuit is 7 hours, 3 minutes and 12 seconds an average speed of 88.32 mph (142.139 km) for 84 laps