Emerald, the third and largest moon of Topaz II, is home to the Emerald buzzbird. These charming birds produce a sound that has a calming effect on humans, and many are exported to other, less relaxed, planets. During Emerald's spring, however, the inhabitants must stay indoors and refrain from operating heavy machinery, as the sound made by thousands of flocking buzzbirds can put anyone to sleep in an instant. In Topaz system and part of the Rebellion.
On the net: Emerald City,