Perhaps the most environmentally unfriendly planets in the
galaxy, Class Y: Demon worlds are inhospitable to life in
every way imaginable. Most often found in the hot zone of a
star system, these worlds possess extremely thick, highly
toxic atmospheres which are plagued with violent storms
that discharge thermionic radiation; surface temperatures
exceed 200°C, and winds may reach 500kph. Incredibly, a
type of biomimetic life form was discovered on a Class Y
planet in the Delta Quadrant in 2374.

Although Class Y planets are extremely rare in the universe,
they are generally unremarkable, average-sized planets
when their harsh atmosphere is taken out of the equation.
The surface is predictably barren, and composed primarily of
iron, deuterium, and silicate rocks, with a diameter between
10,000 and 15,000 kilometers.
AGE
DIAMETER
LOCATION
ATMOSPHERE
SURFACE
INNER CORE
AVERAGE TEMP
EVOLUTION
HABITABILITY
2-10 billion years old
1
0,000 - 15,000 kilometers
hot zone
t
urbulent, with toxic radiation
barren
; iron, deuterium, silicate rocks
molten iron
, sulfur
2
00°C
none
o
nly rare biomimetic life