Spat (unit)

The spat (symbol sp), from the Latin spatium ("space"), is a unit of solid angle. 1 spat is equal to 4π steradians or approximately 7004412530000000000♠41253 square degrees of solid angle. As such, it is the solid angle subtended by a sphere at its centre.

The spat (symbol S) is also an obsolete unit of distance used in astronomy. It is equal to 7009100000000000000♠1000000000 kilometres (1 Tm or 10¹² m). It is about 6.6846 astronomical units (AU), 6996105700000000000♠1.057×10⁻⁴ light-years or 6995324000000000000♠3.240×10⁻⁵ parsecs.