Dark Side of the Moon Tour – A Piece for Assorted Lunatics", the name under which it made its press debut in February 1972 at London's Rainbow Theatre. The title changed for the first part of the US tour to "Eclipse (A Piece for Assorted Lunatics)" during April and May before reverting to "Dark Side of the Moon – A Piece for Assorted Lunatics" in September for the second part of the US tour and finally released in 1973 under the title of "The Dark Side of the Moon". Remarkably, at its first full live performance at Guildhall, Portsmouth, England on 21 January 1972, most of
Orbit of the Moon rotational axis of the Moon seems to rotate towards and away from Earth during one complete orbit. This is referred to as "latitudinal libration", which allows one to see almost 7° of latitude beyond the pole on the far side. Finally, because the Moon is only about 60 Earth radii away from Earth's centre of mass, an observer at the equator who observes the Moon throughout the night moves laterally by one Earth diameter. This gives rise to a "diurnal libration", which allows one to view an additional one degree's worth of lunar longitude. For the same reason, observers at