Sive

**Sive** is the fourth and only rocky planet in the Kerbos System. It's also one of the two planets in the system known to have life.

## In-Game Description

"*Sive is the only rocky planet orbiting Kerbos, and probably one of the most interesting ones too. The planet was believed to have once been much more like Kerbin in the past, with large oceans and continents, but the oceans have since receded away. Life on the surface has recovered, nonetheless, and the planet is about as life-rich as ever, with ecosystems on land, in the sky, and even in the places between. Scientists highly recommend visiting this strange alien world!"*

## Physical Characteristics

Sive is well known among the scientific community for being a planet that shouldn't harbor life, yet has a large abundance of life. Believed to have been more like Kerbin in the past, Sive may have once been host to large oceans and smaller continents. However, interference from Laevo and Jove pushed Sive towards the inner habitable zone, causing the oceans to evaporate. Due to a low gravity and dense atmosphere, most species recovered and became solely aerial, living a life entirely in the sky.

Sive's surface is made mostly of grasslands and deserts, with small forests dotting the surface. A major feature of Sive is its large sea in the northern hemisphere. However, this sea is filled with bacteria that has absorbed one of the ancient oceans. To kerbals it is more of a dark purple desert, but to many lifeforms it serves as an effective food source. Many spots on Sive are also flat plains with large amounts of salt on them, which are likely old seafloors.

Although no oceans and seas exist on the surface, liquid water is still very possible and exists in multiple lakes on the planet.

## Atmosphere

Sive's major component is that it has a dense atmosphere, almost twice as dense as Kerbin's. The dense atmosphere allows life to live an aerial life. It also transfers heat more efficiently than on Kerbin.

The atmosphere is similar to Kerbin's, made mostly of nitrogen and oxygen. However, the atmosphere has larger amounts of oxygen and water vapor than on Kerbin.

## Climate

Sive's climate is very temperate, although sometimes balmy. Temperatures range anywhere between 5° and 40° Celsius, depending on the time of year and transits of nearer planets. Unlike weather on Kerbin, which is driven by the oceans, the weather on Sive is driven by temperature differences on the land. Because of this, it almost never rains, although storms are possible. Storms are frequent around the Bacterial Sea to the north, as it is in large contrast with the rest of Sive's land as far as color goes.

## Life

Sive is well known for its very alien biosphere, extremely different from any observed on other planets. The main factor is its dense and humid atmosphere, which allows for aerial life similar to creatures in an ocean.

Life in the skies of Sive is as abundant as in the oceans of Kerbin. Countless tiny organisms, such as aerial plankton, spend their whole lives floating in the skies of the planet and make up the main food source of most of Sive's air-borne fauna. These minute creatures are so numerous that they sometimes darken the sky. Many of the large air creatures of Sive are floaters, rather than flyers, having large hydrogen or methane-filled bladders to stay aloft. The largest of these floaters attain a wingspan of over 300 meters. Many aerial predators propel themselves through the air by combusting methane. Some small creatures have a biological version of a ramjet engine, with a turbine of bone and gristle, allowing for speedy propulsion.

The ground-dwelling creatures show a great diversity in morphology, though they all share some common characteristics. Sive's terrestrial fauna is divided in four categories, each category from a common ancestor: monopedaliens (one leg), bipedaliens (two legs), tripedaliens (three legs) and quadrupedaliens (four legs). Nearly all predators on Sive are liquivores: they secrete special enzymes to liquefy their meal before consuming it, similar to spiders on Kerbin. One of the most notable traits of Sive's fauna is the lack of eyes. Instead, the organisms rely on echo-location, similar to Kerbin's bats. Despite being blind to visible light, the organisms are able to detect light in the infrared spectrum due to thermoreceptors similar to those of Kerbin's snakes. Many creatures of Sive are bioluminescent, and the light they produce is visible both in the infrared and the normal spectrum. The lightshow is so spectacular you could even see lights in space. Most organisms of Sive are warm-blooded and full of energy. Both predators and herbivores are known for achieving great speed when running.

Another interesting fact about Sive's life is that many species exhibit properties characteristic of both plants and animals, belonging to no known kingdom on Kerbin.

### Possibilities of Intelligent Life

Fossil records show that a species of massive, floating creatures used to live on Sive. The species, named the Keosapiens by kerbal scientists, appears to have been at the level of cave kerbals, using rudimentary tools and being able to cooperate with other members of their species. However, like any other potentially intelligent civilization, these creatures were wiped out by unknown causes. Very little trace of them remains.

## Trivia

* Sive is inspired on the fictional planet Darwin IV.