Jool

Jool is a gas giant and the fifth planet of the Kerbolar star system. It is the most distant of the five planets and the hardest to reach. It is one of the most appealing targets for missions, however, because of its large and complex system of four moons: Laythe, Vall, Tylo and Bop.

Atmosphere

Aerobraking in Jool's atmosphere. Although Jool has a radius ten times greater than Kerbin, its atmosphere begins approximately twice as high (138.2 km). It is also extremely dense, well suited for aerobraking from a high-speed inter-planetary intercept. In general, the atmospheric pressure on Jool at an altitude expressed in meters is: $p_{j}=15\ e^{-altitude/9000}$ Closer to the surface, the physics of the game start to break down. Due to its extremely thick atmosphere, terminal velocity is so low that lighter spacecraft will not even need parachutes or retrorockets. It is not impossible to land on its solid surface, though spacecraft are inevitably and invariably devoured by the Kraken. If a kerbonaut is put on EVA he will not be destroyed, making long term landings feasible.

Natural Satellites

The ocean moon Laythe, about to eclipse Jool. Jool has four natural satellites: The ocean moon Laythe, currently the only moon possessing an atmosphere, is the closest to Jool and second largest of its moons. Due to its high orbital velocity, it is somewhat challenging to reach. Next to Eve, it's size and composition make it one of the most similar celestial bodies to Kerbin The ice moon Vall, which is the third largest and second closest. Its orbital path and velocity sit almost exactly between Layth and Tylo. The rocky moon Tylo, similar to Kerbin's Mun, although it has similar gravity to Kerbin. It is the third and largest body orbiting Jool, and is perhaps the easiest of the four to reach, with a stable orbit, large gravity well, and (relatively) slow orbital velocity. The captured asteroid Bop, the smallest body orbiting Jool. Due to its distant, erratic orbit and low gravity, it is also challenging to reach. Laythe, Vall, and Tylo are in a Laplace resonance, with orbital periods of 1:2:4 respectively.

Gallery

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  Jool in 0.17.

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  Jool and its moons in 0.17.

Changes

0.17

• Initial Release