A terraforming candidate water world (2 b) orbits a wide-ringed class Y dwarf star. The planet's atmosphere is so thin and clear that it appears as a blue marble with pure white ice caps.

Orbiting it closely, every 6.2 hours, is a contrasting nested moon, (2 b a). The surface provides three contrasting landscapes: dark volcanic rock, sulphur, and ice. The moon is also volcanic in nature, and is crossed by impressive canyons.

The nested moon orbits the planet so close that from its surface, the view of its blue marble parent planet dominates the sky. For Commanders who have spent long weeks in the darkness of space, the colour of this world provides a welcome rest for the eyes.

The system is named after Mithras, the sun god and central deity of Mithraism, a Greco-Roman mystery religion.