| Position | Name | Class | Diameter | Density (Composition) | Gravity |
|---|---|---|---|---|---|
| I | Talos I | B | 7,380 km | 4.4 (Low Iron) | 0.46g |
| II | Talos II | H | 12,284 km | 4.3 (Low Iron) | 0.75g |
| III | Talos III | L | 14,785 km | 5.5 (Medium Iron) | 1.16g |
| IV | Clesik (Talos IV) | M | 19,200 km | 3.25 (Low Iron) | 0.89g |
| V | Talos V | D | 12,210 km | 2.5 (Silicate) | 0.45g |
| VI | Talos VI | J | 58,210 km | 1.7 (Gas Giant) | 1.41g |
| VII | Talos VII | J | 63,239 km | 1.3 (Gas Giant) | 1.17g |
| VIII | Talos VIII | J | 67,718 km | 1.4 (Gas Giant) | 1.35g |
| IX | Talos IX | J | 64,822 km | 1.8 (Gas Giant) | 1.66g |
| X | Talos X | J | 84,095 km | 2.1 (Gas Giant) | 2.52g |
| XI | Talos XI | J | 68,978 km | 1.7 (Gas Giant) | 1.67g |
Traditional Name: Clesik (Talos IV)
Talos IV was the inhabited M-class fourth planet of the Talos system, which was a part of the Talos star group. Talos IV, known as Clesik to its native Talosian civilization, has not been completely surveyed, and so Starfleet knows little about it. The results of Starfleet's contact with the planet are classified.
Very little information about Talos IV has been declassified at this point. What is known is that Talos IV had a thriving warp-capable population, until hundreds of thousands of years before 2254 when a nuclear war caused a near-extinction-level event. Talos IV regained its ability to support surface life by the mid-23rd century. The planet's deep underground had been inhabited by the Talosians, who had evolved as an old and weakened species with enormous mental powers.
In 2254, the planet was visited by the Federation starship USS Enterprise – under the command of Captain Christopher Pike – after receiving a distress call faked by the Talosians. With the discovery of the extreme threat of the Talosians' powers of illusion, Starfleet issued General Order 7, forbidding any travel to Talos IV, under penalty of death. The death penalty portion of General Order 7 was rescinded in 2290, but the Talos star system remained under Federation quarantine.
The quarantine of the star system was further reduced in 2320, only forbidding contact with planet Talos IV itself while opening up the potential for Starfleet and Federation vessels to explore the other worlds of the system. Talos IV remains under quarantine today; it is rumored that Starfleet has been conducting some activity related to the planet over the last few years but if true these efforts remain classified.