Pan is a small inner moon of Saturn that orbits inside the Encke gap of the A ring.
Characteristics[]
Pan has an average diameter of 30 km. It has a spherical shape, with a large, visible and non-uniform equatorial ridge, made of matter accreted from the ring. The moon shows presence of canyons that cross the poles, as deep as 1 km, together with possible tracks of other former ridges. There are no large craters. The canyons might be a result of continuous erosion, caused by ring particles. Also, they show that the moon sometimes changes its rotation axes.
Pan has one or two craters, which are less then 1 km in diameter and are probably made by matter accreted from the ring. Its surface must be covered with a layer of dust. However, this dust is in fact water ice.
With a main density of 0.42, Pan must be composed of porous water ice, without a metal or silicate core. However, the moon must be made of solid material and not a pile of rubble, or Saturn's powerful gravity will tear the moon apart. The equatorial ridge must be made of smooth material.
Pan is responsible of keeping the Encke gap open, as it constantly pulls matter out of the gap. It orbits Saturn in 13.8 hours, a bit faster then the inner ring particles and a bit slower then those in the outer ring.
Because the Encke gap is far larger, Pan is less impacted by dust and particles from the ring. However, its equatorial ridge rises close to the Roche limit, which means that the moon cannot grow larger then it is. If the equatorial ridge grows more, it will lose matter. This phenomena creates a ringlet that orbits in the gap at some distance from Pan.
Unlike Daphnis, Pan orbits in the same plane with the ring, so it does not create significant waves in the ring structure.
Local Environment[]
The Encke gap is large enough to offer a safe passage for passing ships. At the edges of the ring, near the gap, matter circles faster or slower, with a difference of speed that reached up to 10 km/h. Sometimes, particles from the ring are disrupted from their orbits and forced into the gap, hitting the moon, with speeds that don't exceed 10 km/h.
Matter that is lost from the moon into the ringlet, as well as matter that comes to the moon from the ringlet, moves very slow, with less then 3 km/h.
Because of this, a base will be affected by collisions. However, impacts will be not like those on Earth's orbit, which are felt like bullet impacts or even worse. On the surface of Pan, impacts are felt like if someone is throwing in a wall with sand, grabble or rocks. Thick walls are able to protect a colony from such impacts.
Pan lies deep inside Saturn's magnetosphere, protected from the solar wind. Saturn does not have a powerful radiation belt like Jupiter.
The Colony[]
Pan is small and made of water ice, with little amounts of impurities. This moon does not contain metals, silicon or organics in large amounts to build a colony. Everything needed will have to be imported from elsewhere. The rings are also made of water ice, with only little impurities. So, building a self-sustaining colony is not an option. The colony will not sustain itself by mining operations or by hosting an industrial center. Even worse, the rings are a natural reservoir of dust and larger particles, which can impact the moon. This will affect navigation.
Still, because on Cassini images we are able to see canyons and craters on the surface, we can assume that impacts are not too often. Most matter from the rings fall on the equatorial ridge, making the poles far safer. Also, given the size of the equatorial ridge, we can speculate that Pan changes its axis only on rare occasions.
The best place to build a base is close to the poles. Still, many structures will be built underground, protected from impacts and from cosmic rays.
The Pan base will be a good destination for tourism. In fact, it does not have any other choice.
Energy used in the base can be solar, but solar panels will be covered with dust and destroyed by impacts. Also, Pan rotates with the same tilted axis like Saturn. Because of this, there will be long polar nights. Building two solar farms, one at each pole, could be a solution, but they must be interconnected and the only connection safe enough is through the center, which is very expensive. Also, large solar panels will affect the landscape and will not be a good attraction for tourists. A nuclear generator is a better option, since it will be smaller, will operate unaffected by seasons and will be cheaper.
Pan colony will sustain itself from tourism. Therefore, many touristic attractions must exist. The base will have a zero-G amusement park, a casino, underground gardens and parks, many clubs, restaurants and other attractions.
Because Pan is much larger then Daphnis, it can host a large underground greenhouse that can produce food and oxygen for the colony. However, rich tourists will prefer to buy exotic food that will be imported from other moons of Saturn. Many goods will be shipped from the other moons of Saturn.
The moon is made of porous water ice, which is a very good insulator. However, all underground or surface constructions need to be insulated in order to preserve heat. Anything built on the surface needs to be shielded against meteorites. At the poles, impacts will be rare, but any hull breach is potentially deadly.
Because a Saturnian year lasts 29 Earth years, polar days and polar nights are very long. If we build the base close to one pole, it will experience a long polar night, a thing that is not too nice for tourists. Instead, it should be better to build two small colonies, one at each pole, probably linked through a central tunnel.
Many people will like to travel on the surface or fly to the rings. For this kind of activities, Pan base will have space suits and spaceships that can be rented (see below). However, knowing the risks, all suits and all ships must be equipped with radio transmitters.
Tourism[]
Pan will be a good touristic attraction. People have many things to see here.
At the base. First of all, the colony must offer many touristic attractions. There will be a zero-G amusement park and a casino. In addition, clubs, restaurants and underground gardens will be visited by many. It is also good to build a museum dedicated to the Saturn rings, that will include everything, from copies of the first manuscripts depicting the rings to replicas of the spaceships that explored them.
The main attraction will be the rings of Saturn. This is what will bring many people here. From the base, behind reinforced windows, people will be able to see them.
At the moon. Pan has a very low gravity compared to Earth. The escape velocity is 15 to 20 km/h. With other words, an astronaut will have no chance to be lost in space while walking on the moon. Walking will be impractical. Moving on the surface could be done at best by jumping. Still, one small uncontrolled jump can send you hundreds of meters away.
Even with a space suit, oxygen tanks, propellant and a pocket engine, a human will not weight 1 kg. Because of this, tourists can travel on the surface with the help of a small engine. They can leave the base, explore the canyons and get close to the equatorial ridge.
As people will get closer to the equator, the risk of an impact increases. To prevent this, each costume must be equipped with a small radar and a warning system. If a chunk of ice coming from the ring is approaching, the costume must warn its user and even take initiative, firing the engine if needed.
Small trips. Many people will be tempted to go to the equatorial ridge or even to cross the moon from one pole to the other. This will be possible using space costumes with larger autonomy or with small ships. Some people will do this on their own, while others will require a guide.
Even more people will be tempted to go to the rings. This can be done easily with the help of a ship. There, people will watch the rings from close distance and will even dare to visit them. Inside the rings, particles don't move very fast, as we are familiarized from sci-fi movies. Instead, it is a very calm place. The main risk is if you travel too fast, compared to the particles. They all move with similar speeds. Also, there is a lot of dust in the rings, which creates a serious problem, since this dust is electrically charged and can be accreted on all windows.
It is possible that there will be regular trips between the moon and the edges of the ring. There, people will wear space suits and will explore the rings. It will be a unique experience. The rings of Saturn are surprisingly narrow (about 30 m wide), but also very dense. It will be very easy to cross them from one side to the other.
Larger trips. Touristic ships will travel further away. These ships will fly at some distance from the ring plane, to avoid hazards. People will see from very close ring gaps and denser parts. They will see propellers and dust clumps. A ship can travel above the ring plane, where everything is illuminated by the Sun. Then, it can slowly cross through the rings and return below the ring plane, where people will see how solar light gently passes through the rings.
When the moons are properly aligned, it is possible for a spaceship to reach Daphnis or a nearby propeller.
Sports. Saturn provides an unique environment for racing sports. These include driving a ship inside the ring or closely above it or flying inside a gap. Amateurs will be tourists, willing for some adrenaline. However, there will be many expert pilots, risking their lives to become a champion.