Lunar calendar average length of the synodic month is days. Thus it is convenient if months generally alternate between 29 and 30 days (sometimes termed respectively “"hollow"” and “"full"”). The distribution of "hollow" and "full" months can be determined using continued fractions, and examining successive approximations for the length of the month in terms of fractions of a day. In the list below, after the number of days listed in the numerator, an integer number of months as listed in the denominator have been completed: These fractions can be used to construct a lunar calendar, or in combination with a solar calendar
Apollo 15 operations on the Lunar surface triangles are panorama stations. Apollo 15 operations on the Lunar surface Apollo 15 lunar surface operations were conducted from July 30 to August 2, 1971, by Apollo 15 Commander David Scott and lunar module Pilot James Irwin, who used the first lunar rover to make three exploratory trips away from their landing site at the base of the Apennine Mountains, near Hadley Rille. They collected a total of of lunar surface material during 18½ hours outside their lunar module, "Falcon". At 104 hours, 30 minutes and 12 seconds GET the descent engine of "Falcon" ignited. Burning at about 10% for