The Lunar 100 was created by Charles A. Wood who states: "The
Lunar 100 list is an attempt to provide Moon lovers with
something akin to what deep-sky observers enjoy with the Messier
catalog: a selection of telescopic sights to ignite interest and
enhance understanding. [It is]... a selection of the Moons 100
most interesting regions, craters, basins, mountains, rilles,
and domes."
Woods challenges "...observers to find and observe them all and,
more important, to consider what each feature tells us about
lunar and Earth history."
To find out more about the Lunar 100 see the Sky & Telescope web
site at: http://skyandtelescope.com/observing/objects/moon/article_1199_1.asp.
The Lunar 100 features are arranged from the easiest to view to
the most difficult. The Moon itself is L1. L2 is Earthshine, and
L3 represents the dichotomy between the Lunar highlands and the
Lunar Maria. While the Lunar 100 are concentrated all on the
nearside of the Moon, they can not be seen in a single night or
a single month. Some of them require special lighting conditions
or phases of the Moon, and others, in addition, require very
favorable librations of the Moon to bring them into view. The
Lunar 100 is an observing list. However, the equipment at the
3towers Observatory was used to image the Lunar 100, mainly
using the web cam techniques detailed.