Planet Deca

Affiliation:	Republic of Deca⠀
Type:	Terrestrial⠀
Orbital Parent:	Archono-000 Prime⠀
Semi-major axis:	1.19 AU⠀
Sector:	Archono Cluster⠀
Galaxy:	Andromeda
Diameter:	12,800 km⠀
Mass:	6 octillion kg⠀
Density:	6.833 g/cm^3

Planet Deca, also known as Decania C and Archono-000c, is a Temperate Marine Terra class planet with artificial modifications courtesy of Decahedron Technologies, and the former home of the Republic of Deca and the Archono Union. Planet Deca has two moons, Arfon and Ornoa.

Atmosphere and Ocean

Planet Deca's atmosphere is similar to that of Earth's, optimised for human life with an surface atmospheric pressure of 100,500 pascals. The atmosphere is primarily composed of (in descending order): Oxygen, Carbon Dioxide, Nitrogen (mostly in upper layers) and Helium (mostly in upper layers).

There are two large artificial oceans that finished construction in 2 APD., being the Ionian Ocean and the Dergan Sea.

Timeline

Pre-Archonoian

Little is known about Planet Deca's origins, however we believe it may have had a similar origin story to that of Earth. It was formed as part of the Archono-000 system 1 billion years ago, and experienced a collision event with an unnamed Mercury-size object. The collision released debris into orbit that concentrated into a point that is now known as Arfon. It is also believed that this collision released oxygen and created an atmosphere. Ornoa is believed to have been its own dwarf planet originally, however at one point was captured by Planet Deca and became a moon.

Decanian Colonisation

In 1 BPD, probes were sent to the surface of Planet Deca, operated by DecaSpace, to check for habitability. It was found that Planet Deca has a viable atmosphere, however limited water and no life. Following through the next year, various more probes were sent to implant Earth species into Planet Deca, as well as breaking down the surface into a viable soil, converting the excess atmosphere into water with hydrogen collected from Archono-000 Prime.

In 0 APD, humans colonised Planet Deca, and established the Republic of Deca to govern it.

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(Further details between these events are currently not available to the public)

Necronian Invasion

In the year 577 APD, Planet Deca was evacuated due to the ongoing invasion conducted by Necro, which was deemed impossible to stop. 6 billion of the 6.1 billion were successfully evacuated onto the Wayfarer fleet and transported to New Archonia over a 12-year journey.

Since the departure of the Archono Union, the planet has been under the rule of Necronian Zombies. As of 591 APD, expedition probes report that the zombies may be growing sentience and their own civilisation. Further details are currently unknown.