Lunar 100 – Object 37
Bailly is an enormous, ancient impact structure near the Moon’s southwestern limb, so heavily eroded that its original basin form is barely discernible. Its multiple ring remnants are worn down to low, irregular ridges, and the interior is filled with countless later craters that obscure the basin’s outline. Bailly is included in the Lunar 100 because it represents a barely recognizable basin, illustrating how extreme age and continuous bombardment can degrade even the largest lunar impact features.