Tylo is not just the largest of the five moons of Jool, but the largest moon overall in the KSP solar system. It has a rocky surface. It is extremely challenging to land on because it possesses a similar gravity well to Kerbin itself, while lacking the benefit of an atmosphere to brake in. But due to its large gravity well, it is ideal for performing a gravity assist to enter or leave the Jool system safely and with minimal fuel consumption.
Having a spacecraft orbiting very close to the surface can give you orbit periods of about 29 minutes going about 2,170 m/s. Like the other large Joolian moons, Tylo is tidally locked. Synchronus orbits around Tylo are not possible, as they would lie outside of its SOI, at a radius of 14,758,067 meters.
Tylo is KSP's analog to the Jupiter moon Ganymede.
Tylo is a large rocky moon of Jool. It has a varying elevation between 0 meters (Tylo baseline height) and peaks of more than 11290 meters.
Tylo's surface looks similar to that of Mün, but has much fewer impact craters (especially on the side facing away from Jool) and is more uneven.
Due to the coloring of the surface of Tylo, it is likely that it is covered in a rhyolite layer of rock, nickel, a little cobalt, some sort of ice and dust, spread by meteorite impacts. Although very large in comparison to other moons, it is unlikely that it is a captured planet. For a planet of this size, Jool would have to be much larger and denser to produce a large and strong enough gravitational well. It is a mystery why Tylo hasn't formed an atmosphere.
- Initial Release