Thea

Thea, or Theeya, is the larger of the two moons of Helevos, the smaller moon being Themsa.

Thea is a spheroid approximately 1582 km in diameter. I's surface is covered with an ochre iron-silicate dust with mountain ranges of lighter grey rock. In the night sky it appears as a disc less than half the size of Earth's moon, and much less bright. It's surface gives Thea a pinkish light in the night sky.

The moon is covered with craters but its surface consists of deep fines of dust which flow very slowly over geological time to fill in and blur the edges of craters. Regular micro-meteor impacts throw up clouds of dust which take a long time to settle in the low gravity, obscuring the surface and giving the moon a blurry appearance.

Thea orbits the planet in 34 days, waxing and waning from dark to fully bright. Due to the differentiation of colour on the moon's surface, the apparent colour changes over time. As a waxing crescent (left side lit) the moon is a deep ochre red. When the opposite waning crescent is lit, it is almost pure white. Consquently the red crescent is called the blood moon, and the white side the virgin moon, with many variations in different cultures.

Thea has long been the moon's official name, from the ancient Miyarrain language. It also has many regional names, such as The Eye, the Red Moon, the Bloodmoon, or just the Moon.

Its reddish colour, monthly cycle and seemingly shifting appearance has led peoples to associate the moon with changes in health or war. Divination by observation of the moon is called themsamancy.