Siano

Description
Siano, named for an ancient asari philosopher known for being a contrarian, orbits Dirada at a retrograde. It is believed to be an object that fell into the system millions of years of ago from parts unknown. The outermost of Dirada's two inner asteroid belts is thought to have been a small planetoid that was broken up by Siano's passage into the system. Siano is formed of low-density rock and is tidally locked to Dirada; the same hemisphere always faces the star. There is evidence that a complex of artificial structures once existed in the north of the sunward-facing hemisphere, but they have been badly degraded by millennia of heat and radiation. Several bunkers of radioactive waste, apparently byproducts of primitive fission plants, have been discovered on the far side.