The Backwards Moon happens only once every 210 years. It is caused by the moon and the planet's rotation on their respective axises; there is a brief moment in time where the moon's crescent opens to the right rather than to the left. The Backwards Moon is depicted on the emblem of the House Turcott.
The Backwards Moon has been known to coincide with major cataclysms throughout history, such as the end of the 1st Great War and the appearance of the Curella virus.