(glossary entry; plural = Fossae)
One of 18 different categories of lunar features recognized in the current system of IAU nomenclature. The IAU defines a fossa as a "long, narrow depression". The term is used as prefix to the feature name.
This term was used, pending IAU approval, on a number of the LTO charts prepared for NASA by the Defense Mapping Agency in the early 1970's as explained in Ashbrook, 1974. Although the term is commonly used by the IAU on other planets, it was (according to Whitaker) disallowed for use on the Moon in 1976. There are currently no features on the Moon designated as fossa by the IAU. Of the many "fossae" that were proposed, only two were tentatively approved, and they are both now known by different names: Fossa Casals is now known as Rupes Cauchy and Fossa Cauchy is now known as Rima Cauchy.
- Jim Mosher
List of Fossa