The spat (symbol S), from the Latin Spatium ("Space") is an obsolete unit of distance used in astronomy. It is equal to one billion kilometres (1 Tm or 1012 m). It is about 1.057×10-4 light-years or 3.240×10-5 parsecs.
References
- Nouvelle encyclopédie du monde, Éditions Leland Ltée. (Librairie Aristide Quillet), Montréal/Toronto/Paris, 1962, vol. 16, p. 5426
