Class N reducing planet

For other uses, see Class N.

Class N
Classification:	reducing
Age:	3–10 billion years
Diameter:	10,000-15,000 km
Location:	ecosphere
Surface:	high-surface temperature
Atmosphere:	greenhouse effect, extremely dense with carbon dioxide and sulfides
Evolution:	class M (through terraforming)

In Federation planetary classification, a Class N or class-N reducing planet was a terrestrial planet with high surface temperature and a dense, acidic atmosphere due to a greenhouse effect. Water only existed as vapor. Venus was the textbook example of a class N planet. (ST reference: Star Charts)

The class N-based species Agni referred to such worlds at hot realms. (TOS novel: The Captain's Oath)

Specifics

Class N worlds were characterised by a high surface temperature fuelled by greenhouse effect, and an extremely dense atmosphere. The latter was comprised of carbon dioxide and sulfides.

A class-N reducing planet had an age ranging from 3 to 10 billion years and a diameter of 10,000 to 15,000 kilometers. Reducing planets were located in the ecosphere of their parent stars. Venus, the second planet of the Sol system, was the textbook example for a class N reducing planet. (ST reference: Star Charts)

Native was possible on some class N planets. Starfleet categorised these as Class-N life-forms. In addition, humanoids from class M conditions could colonize class N environments with advanced technology and artificial structures. In the 23rd century, the Federation maintained floating cities in the atmosphere of Hearthside (Regulus I). (TOS novel: The Captain's Oath)

By the 24th century, the Federation had mastered building structures that could last in surface conditions. Around that time, terraforming such a world into class M conditions was possible. (SCE - Aftermath eBook: Ishtar Rising)

History

An Agni cylinder ship.

In the 23rd century, the Agni were refugees and had to leave their homeworld. They were repelled by various "cold beings" - species from non-Class N environs - and were unable and unwilling to communicate with Starfleet when they entered Federation space. Their unauthorised colonization - or "squatting" - of Hearthside and 88 Leonis III in 2264, let to skirmishes and tense negotiations until common ground was established. (TOS novel: The Captain's Oath)

In the 24th century, the Federation attempted to terraform Venus in the Sol star system. The effort nearly failed and led to a creation of an accretion disk, forming into a future moon, Venus Felix. (SCE - Aftermath eBook: Ishtar Rising)

Class N planets

• 88 Leonis III
• Agni homeworld
• Hearthside (Regulus I)
• Legira II
• Syllerran I
• Syllerran II
• Syllerran III
• Syllerran IV
• Venus (Sol III)

Appendices

Connections

Planetary classification
numeric:	class 9 ("Q'tahL"-class)	alphabetical:	class A class A geothermal class A gas giant
class B class B geomorteus class B gas giant	class C class C geoinactive class C reducing	class D	class E
class F class F geometallic class F geocrystalline	class G class G geocrystalline class G desert	class H class H desert class H geothermal	class I class I gas supergiant ("Q'tahL"-class) class I metallic/silicate
class J class J gas giant class J moon	class K class K silicate/adaptable class K transjovian	class L	class M ("Minshara"-class) class MZ
class N class N reducing class N pelagic	class O	class P	class Q
class R	class S	class T	class Y ("Demon"-class)

Appearances and references

Appearances

• TNG episode: "Night Terrors" (first reference)
• ST reference: Star Charts (first appearance)
• SCE - Aftermath eBook: Ishtar Rising
• STO - Delta Quadrant mission: "Mindscape"
• STO - With Friends Like These... mission: "Legira System Patrol"
• TOS novel: The Captain's Oath