3.6 Planetary Classes Q–T (Variable, Ultragiant)

Reference data for planetary classes Q, R and the Ultragiant classes S–T, listing age, diameter, location, surface, atmosphere, life-forms and examples for each.

Class Q Variable planet, a mottled green-and-grey world with patchy water and ice.

Class R Rogue planet, a dark green world with swirling cloud patterns.

Classes S-T Ultragiant, a vast pale gaseous world.

Class Q — Variable

Age: 2-10 billion years
Diameter: 4,000-15,000 km
Location: Hot Zone/Ecosphere/Cold Zone
Surface: Ranges from molten to water and/or carbon dioxide ice, due to eccentric orbit or variable output of star
Atmosphere: Ranges from tenuous to very dense
Example: Genesis Planet

Class R — Rogue

Age: 2-10 billion years
Diameter: 4,000-15,000 km
Location: Interstellar space, cometary halos
Surface: May be temperate due to geothermal venting
Atmosphere: Primarily volcanic outgassing
Life-forms: Non-photosynthetic plants, animal life
Example: Dakala

Classes S-T — Ultragiant

Age: 2-10 billion years
Diameter: 10-50 million km (Class S); 50-120 million km (Class T)
Location: Cold Zone
Surface: Tenuous, composed of gaseous hydrogen and hydrogen compounds; radiates considerable heat
Atmosphere: Zones vary in temperature, pressure and composition; water vapor may be present
Life-forms: Unknown