Airy (lunar crater)

Airy is a lunar impact crater located in the southern highlands of the Moon. It is named after the British Astronomer Royal, Sir George Biddell Airy. The crater lies within the much larger and older crater, Playfair, positioned on Playfair's southern rim.

The rim of Airy is well-defined and circular, although somewhat eroded. Its interior is relatively flat and featureless, with a few minor irregularities. A notable feature of Airy is its small, cup-shaped craterlet located on the center of its floor.

Airy is significant due to its role in establishing the lunar coordinate system. In 1961, the International Astronomical Union (IAU) defined the center of Airy's craterlet as the fundamental point of the selenodetic control network, effectively serving as the "Greenwich" of the Moon for measuring longitude. The precise coordinates of this craterlet were crucial for creating accurate lunar maps and geodetic surveys.