32' 56 Librations Bailly (crater) April 11 Shi Shen (crater) April 26 Belkovich (Walled Plain
) April 27 For key dates, yellow dots on the map indicate what part of the Moon's limb is tipped the most toward Earth by libration under favorable illumination.
This 60-mile-wide crater, sometimes likened to a "walled plain
," lacks a central peak, and has a lava-filled floor that appears darker than its surroundings.
The section's text offers a few questionable geological explanations and makes liberal use of the outdated term "walled plain
," a phrase that harks back to the days when the impact nature of craters was not widely accepted.
Day 8 Situated on the northern edge of Mare Imbrium (Sea of Rains), the crater Plato is an elliptical walled plain
with no central peak and a lava-filled floor that appears darker than its surroundings.
Day Eight Situated on the northern edge of Mare Imbrium (Sea of Rains), the crater Plato, called the Great Black Lake by observers during the 1600s, is an elliptical walled plain with no central peak.
Day Eleven Tucked inside the northern side of Mare Humorum (Sea of Moisture) is the prominent walled plain Gassendi.
But after installing the correctors, the walled plain
Clavius and two of its internal craters came into view.
Not really understanding how craters formed, early Moon mappers demonstrated their scientific mettle by classifying craters into types with a plethora of different names: walled plains
, mountain rings, ringed plains, crater plains, craters, craterlets, crater cones, crater pits, obscure rings, and depressions.