Rilna

Rilna and Isen

69% ice (land- and sea ice)

**Rilna** is a habitable super-Kerbin that is currently experiencing a global ice age.

## In-game Description

"*Planet Rilna is a habitable super Kerbin that is going through an ice age due to the low amounts of greenhouse gases in its atmosphere at this time. As a result, many land creatures that were unable to adapt to cold climates during the past global cooling event became extinct, leaving only lichen-like organisms and small animals alive on land, while ocean life remained mostly untouched. The cool but not unbearably cold climate makes Rilna a great place to build ski and snow resorts, as soon as Kerbals figure out a way to get there first."*

## Physical Characteristics

Rilna is the equivalent of Kerbin if Kerbin was in an ice age. It has multiple continents connected by large glaciers coming from the massive poles. Because of the mass glacial patterns, almost all the land on Rilna is connected to each other, making land travel to any area possible. However, this is only possible because so much of Rilna's surface water is locked up in glaciers. During warmer periods of Rilna's history, the water level gets high enough to cover most of the land bridges and separate Rilna's super continent into multiple pieces.

Due to the cold climate and breathable atmosphere, Rilna is a great place for mass ski resorts.

## Atmosphere

Rilna's atmosphere is similar to Kerbin's in composition. It is composed mostly of nitrogen (N₂), with smaller portions of oxygen (O₂), along with trace amounts of other gases. Unlike Kerbin's atmosphere, Rilna is lacking in greenhouse gases like carbon dioxide (CO₂). This has led the planet into an ice age colder than the last one on Kerbin.

Another difference between Rilna's atmosphere and Kerbin's is that Rilna has a significantly higher amount of ozone in the atmosphere than on Kerbin, which is extremely beneficial to the life there, as it blocks higher portions of the UV radiation blasting from Kerolon.

## Climate

Rilna's climate is comparable to a snowball world in the making, similar to the past "snowball Kerbin" when Kerbin froze over because of a lack of greenhouse gases. For the last few million years the planet has been dropping in temperature and will likely become a frozen world until volcanic activity picks up and warms the surface.

Rilna's climate is determined primarily by the temperature differences between the ice caps and the slightly warmer seas on the surface. Because the temperature differences aren't very radical and the small size of the seas, weather is mostly predictable. However, the cooler temperatures make evaporation less common, meaning there is much less cloud cover in the skies and very little precipitation. Most precipitation will occur as snow, sleet, or hail.

## Life

Life on Rilna has had some trouble adapting over the years. Because Rilna is significantly younger than Kerbin, it hasn't had enough time to develop complex life. However, at the time of Rilna's cooling it was already ahead of what Kerbin's life would have been like at the time. Just before the ice sheets grew, Rilna had plentiful ocean ecosystems and even a few basic land ecosystems with large insect-like and smaller reptilian organisms.

When the freezing started, the first to go out were the ocean reefs and organisms that rely on them, which relied on the warmer waters, similar to coral reefs on Kerbin. Many tropical land plants also went extinct, as well as animals that relied on them for survival. It is regarded as Rilna's largest mass extinction to date.

As far as life that survived, on land most of what survived are pink dome-shaped plants. The plants are shaped like this to avoid heat loss as much as possible. Relying on the plants are small, nearly microscopic insects that feed off them, and feeding on the insects are hexapodal mammal-like reptilian organisms, all remnants of Rilna's past ecosystems. A phenomena observed is a predator-predator relationship between many of Rilna's land organisms, all feeding off of each other. The food chain (which is more like a circle) is still supplied by the plants as a base, but when the land plants go extinct the predators can rely on each other for a few thousand years before their food is exhausted.

Ocean life has had a hard time surviving the ice age. Most organisms grew in size and became filter feeders similar to whales. However, the "whales" on Rilna are arthropod-like organisms. It is believed at the bottom of Rilna's ocean and even under a good chunk of the ice exists ecosystems that rely off of smokers and vents, but they have yet to be discovered.

Although Rilna has large amounts of isolation, it has such little habitable land that the world is still classified as sub-habitable.

## Biomes

Rilna has 6 biomes:

* Shores
* Water
* Inland Water
* Ice Caps
* Tundra
* Frozen Grasslands

## Trivia

* Rilna is the only planet in KSS with pink plant life.
	+ The blue tint is a response from the large amounts of UV radiation from Kerolon.