Iàn Ghealachean

Tellus is one of those lucky planets in that is is a dual-moon system. Speaking strictly by volume, it would technically be a dual planet system with a single moon, but one of the bodies has no atmosphere, no life, at all.
The two bodies orbiting Tellus do not share an orbit of any kind; the smaller, Luna, being much closer than the larger, known as Terra. The smaller is also home to life of several different sorts, including Thri-Kreen, Orcs, Gith, and Ilithids. The two moons are worshipped with varying levels of intensity by all of the peoples of the planet (of course the fact that Life exists upon Luna is a relatively new bit of public knowledge, after the orcs invaded during the The Battle of Craysilt. Ever since, the holiday of Iàn Ghealachean has been celebrated with somewhat less fervor, though any excuse to get together in crowds and alter their mental state would be taken full advantage of by the masses.
An ancient holiday, it happens only once every forty three months, when both moons are full at the same time. It is an especially enjoyed gathering of Singer tribes, when most of them make the pilgrimage to Sgàineadh for a festival. The phenomenon is especially poignant over the reflective surface of the Sea of Glass...there is not a Singer alive who has not written their own musical composition about the Full Moons.

Manifestation

Both of the moons of Tellus are simultaneously full. This lasts for twenty two hours, although the party lasts a month.

Localization

Watching the phenomenon over the Sea of Glass is a profound experience that cannot but change a person.

Type

Natural