CRYONIC WORLDS

These worlds like jovians are made extensively of ices, and are found in the outer system, and most commonly at its periphery. Cryonic worlds are basically very large Kuiper belt objects, balls of ices that may be up several thousand kilometres across, they are thought to be the ‘seeds’ of jovians, though these worlds had not grown large enough to gain appreciable atmospheres or gained enough mass to grow further in their less dense part of the solar nebula. These types of worlds can form anywhere there are ices, though the formation of Jovians tends to capture and destroy them, and large Jovians within the system allow only the outermost worlds of this type to survive. Cryonic worlds have also been noted in young systems in the process of formation. They may also have the following characteristics.

Are distant from the sun, generally found in excess of 3000m km, though worlds of this type may be found up to 500m km though these are rare.

Predominated by ice, usually mostly water, with lesser amounts of ammonia and carbon dioxide.

May have tenuous, appreciable or no atmosphere, but where there is the composition will be dominated by methane and nitrogen, though other organics may play important parts in surface chemistry.

They tend to have relatively dark surfaces, due to the presence of organic compounds, though many examples can be listed of bright surfaced worlds, generally due to bright methane ice, which gives them a distinctive colour.

They tend not to have any magnetic field whatsoever, they are also cryo-geologically dead, though past evidence of cryo-geological processes may be evident.

Surfaces tend to be crated, though their ice nature may remove this over time, especially if surface ices are volatile and sublime easily (methane and nitrogen ices).

They tend to have relatively fast axial rotation periods (compared to inner terrestrial worlds).

Masses vary greatly, but they are all low density, usually less than 2.00, with very little rock in their composition. Cryonic worlds may weigh up to 6 Earths, and as little 0.001 earths, though large ones tend to ‘evolve’ into jovians if conditions are suitable.