Ark Galactapedia

Hades IV is a former planet in the Hades system. Once a sizable terrestrial world, it is split into two large pieces. The leading theory as to the cause of the planet's bifurcation is that it was likely impacted by a weapon of mass destruction during the ancient war that eradicated all life from the system. It's unclear if the world was ever inhabited, but its destruction indicates that it was strategically important to the Hadesians. Any structures that may have existed on its surface were obliterated when the planet was destroyed.