Selenodesy refers to the scientific study of the physical properties and characteristics of the moon. There are a number of synonyms for this term, including lunar geodesy, selenography, and moon surveying. Each of these terms refers to the various methods that are used to study the moon's surface, interior, and orbit. Selenodesy is a relatively new field of study, dating back to the 20th century, but it has gained significant interest and importance in recent years, particularly with the advent of space exploration and the desire to establish permanent human settlements on the moon.