A cousin of the world Yridia III used to be, Magnus is a sterile, rocky moon, whose composition is very similar to Yridia III. It is thought to have been spawned from Yridia III during the time when Yridiae was forming during a time of constant impact from infalling material from the interstellar medium. The moon is not currently used for any purpose.
The moon was named in honor of the founder of House Tarentum, Magnus Kaerner.