Rychri was a Class M planet and a protectorate of The Directorate. It was described as one of the most lush and greenest planets in the quadrant.
The largest city on Rychri was Matalia.
By 2367, the population of Rychri was 7,272,047 Rychrima, including the father-and-sons team of scientists, Muen Alcreat and his sons Erit and Tranar.
An automated distress call was issued in that same year. Upon arrival, the USS Prospect accessed an orbiting sensor platform to find all the inhabitants had disappeared from the surface within the period of a half-hour. (Star Trek: The Prospect Chronicles: "Honor Thy Father")
Matalia[]
Matalia was the largest city on Rychri.
In 2367, two away teams, led by Commander Hahn Jun-Seok, beamed down from the USS Prospect to Matalia to determine where the Rychrima population had disappeared to. (Star Trek: The Prospect Chronicles: "Honor Thy Father")