Gael is the 4th planet and the homeworld of the kerbals, effectively Gaeleans, in the Ciro system, member of the Galilean planets and which replaces Kerbin in Galileo's Planet Pack. For the purpose of maintaining the viability of pre-existing vessels and easing veteran and novice players alike into the experiences this system provides, Gael is designed to share most of its core traits with Kerbin but avoid being a Kerbin clone.
There are custom science definitions for Gael itself and its moons but no other worlds at this time.
"A terrestrial planet. Homeworld of the Kerbals. Despite their penchant for mega-structures, Kerbals make every effort to ensure that the ecological balance of their world is not disturbed, and much of the planet remains an untouched wilderness."
- Galileo Kerman
Gael’s surface consists of about 51% ocean, 45% land, and 4% polar ice caps. All sections of ocean are connected, allowing circumnavigation of the planet. The land is concentrated into three main continents, along with over one hundred islands.
The largest of the three continents, Uakora, covers nearly one-third of the planet’s total surface area, and contains more than two-thirds of all land area. Uakora’s geographic center lies at about 5° N latitude and 25° W longitude. Both Gael’s equator and prime meridian run through Uakora. The western part of Uakora generally lies at a higher altitude and contains more rugged terrain than the east. Uakora has many tall mountain peaks, but none more impressive than the massive Mount Iodos, whose summit reaches 5,939 meters. Uakora is also spotted by several lakes, mostly in the west, and its terrain is sculpted by a huge river system running through its middle.
Gael’s second largest continent is Pligia, whose geographic center lies at about 10° N, 165° E. Pligia’s west coast features a wide strip of mostly low lying and flat terrain. The middle and east of Pligia is more rugged, including several tall mountains near the continent’s center. Gael’s highest peak, Mount Cilos, is located here, reaching a maximum height of 6,375 meters. The Kerbal Space Center is situated on a small island off the east coast of Pligia.
Gael’s smallest continent, Eucria, lies to the southeast of Pligia, at a geographic center of about 45° S, 150° W. Eucria is about half the size of Pligia. The continent contains fewer mountains and more flat terrain than either Uakora or Pligia. Eucria's tallest mountain tops out at 5,635 meters.
Polar ice caps cover both the north and south poles. Almost the entire surface is ice-covered at latitudes greater than 75°.
Gael has a thick, warm atmosphere capable of sustaining a diverse biosphere. It is one of two worlds in the Ciro system where the surface temperature and pressure is suitable for the existence of liquid water.
The atmosphere consists principally of nitrogen (74%) and oxygen (20%), and extends to a maximum height of 70 km above sea level. Air pressure at the surface of Gael ranges from 101.325 kPa (1 atmosphere) at sea level to 36.4 kPa at the top of Mount Cilos. The variation of temperature with height gives rise to a troposphere, stratosphere, and mesosphere. The existence of a stratosphere suggests the presence of an ozone layer, which protects the surface from harmful ultraviolet radiation. Gael’s has a significant greenhouse effect, with surface temperatures averaging 38°C above the planet’s black body temperature.
Gael has a globally averaged surface temperature of 15°C. Sea level temperatures at the equator range from an overnight low of 21°C to a mid-afternoon high of 33°C, at 45 degrees latitude the daily range of temperature is 3 to 14°C, and at the poles the temperature is -22°C. Surface temperature decreases by an average of about 7°C for every kilometer rise in elevation. Gael has no axial tilt and its orbital eccentricity is zero, therefore the planet experiences no seasons whatsoever.
Gael is presumed to have a hydrological cycle with abundant precipitation, evident by the presence of inland lakes and rivers, and substantial cloud cover. However, due to the lack of seasons, the weather patterns are undoubtedly different than we experience on Earth.
Gael’s physical and atmospheric characteristics are so close to Kerbin that it should behave almost identically in terms of flight performance. Pretty much every lessen you’ve learned from the stock game and about craft design, launch profiles, delta-v requirements, etc., will also apply to Gael. There are some tiny differences between Gael and Kerbin, but unless you are making very precise comparisons, you will likely not notice.
The developers have introduced one change, however, that has a significant effect on gameplay. The location of Kerbal Space Center is not on Gael’s equator as it is on Kerbin. This means that any launch from KSC will result in an inclined orbit – about 8.5 degrees for an eastward launch. This introduces an aspect to mission planning and design that new players will have to grow accustomed to.
Gael has 14 natural biomes, three of which are intended mainly for identification purposes but are of course valid for science:
- Inland Water
- Minor Shores
- Uakora Shores
- Pligia Shores
- Eucria Shores
- Ice Caps
The KSC is not on the equator. It sits on a tiny island associated with the northern minor continent Pligia. The last known values for it are:
- latitude = 8.640 N
- longitude = 168.220 W
- altitude = 43 m
- Mount Iodos on Uakora super-continent: summit height of 5,939 m.
- Mount Cilos on Pligia minor continent: summit height of 6,375 m. Its coordinates are 6° 21’ 14” N, 168° 0’ 44” E.
- Along with all the other Galilean planets Gael presents unfamiliar topology including a wishbone shaped ocean dividing the two lesser continents and one super-continent, and that the super continent occupies an entire hemisphere.
- Anomalies can be found on some of this planet's tiny islands.
- The Reefs biome highlights most of the tiny islands, whether above or shallowly below sea level. Along with a high concentration of oceanic karbonite, Gael adds appeal to and highly encourages Kerbal Sea Programs.
- Players need not visit the other worlds with (or without) atmosphere or oceans to find and exploit an immense Karbonite presence. Here on Gael, players are enabled to use the atmosphere and oceans themselves as fuel.
- Terrain scatter is tangible. Clipping a tree or rock while driving a rover or landing (on any Galilean planet actually) will cause damage.
- Gael's moons have different orbits and exchanged gravity amounts to add more novelty to budding space programs.
- Gael's moons have 5 or less biomes each to answer the problem of players' tech trees being completed before space programs go interplanetary.
- The physical characteristics and behavior of Gael’s atmosphere are very similar to Kerbin. The atmospheric model used is the same as Kerbin’s from the Realistic Atmospheres mod.
- Gael's semi-major axis is 382,926,450 m larger and its sphere of influence 492 km smaller than Kerbin. This is due in small part to the slight difference between its own gravity and that of Kerbin, but for the most part due to Ciro's slightly greater mass compared to Kerbol.
- The negligible difference between Gael's and Kerbin's gravity is due to the developers opting not to adopt Kerbin's adjusted gravity value with n decimal digits brought about with the release of KSP version 1.2.0
- The off-equator location of the KSC is intentional to deliver the added challenge of any real world space agency having no facilities on the equator.
- The official adjective for kerbals or other entities associated with Gael is Gaelian. [Gah.el.ee.an] or [Gay.lee.en]
The air pressure at the top Mount Cilos is equivalent to an altitude of 7,850 meters (25,750 feet) on Earth. This would rank as the 21th tallest mountain on Earth, one kilometer shorter than Mount Everest. Considering the slightly lower oxygen content of Gael’s atmosphere, the summit is just inside the “death zone” for humans.
Gael's two flags are both region type and faction type.