Luca (/'lukʌ/ LOO-kuh; oʀᴛʜoᴅox: L) is the smaller and nearer of Iær's two moons. Following a prograde orbit, shadow moves from right to left across its surface, like Earth's moon; it rises in the east and sets in the west. With a more dense composition than Talas and its inner position, Luca has fewer major impact craters; Luca does however feature numerous minor craters, as impact deflection and other impact debris from Talan impacts offset the aforementioned factors to a varying extent.

Luca is a significant component of the major religions of Iær. With its similar apparent magnitude with Luca, there are still some who believe they are the same size, despite evidence provided by the latest telescope technology.