Future Manned Spacecraft Design

Titan has three large seas. However, the seas of Titan are not filled with water, but are filled instead with swirling liquid hydrocarbons. All three of Titan's exotic seas are close to its north pole, and they are surrounded by many smaller hydrocarbon-filled lakes in the northern hemisphere. It's hard not to like Sagittarians, for their openness, generosity, and sociable nature. They are deep thinkers in search of universal wisdom, attracting them to philosophy and religion. Their minds can grasp both the details and the bigger picture: they can think with intellectual precision but also intuitively. That unusual combination of thinking skills allows them to be at the forefront of creative ideas. They are idealistic and care about the state of the world, leading them to take up vocations in medicine, education, religion, and politics. They need to be highly independent in their work and in their personal lives. Dr. Porco further believes that Enceladus's orbit could have been much more eccentric in the past. The greater the eccentricity, the greater the tidal squeezing, and the resulting structural variations produce heat. In this case, the heat would have been saved inside the icy moon, melting some of the ice to replenish the liquid water sea. Dr. Porco continued to explain that "(T)he tidal flexing occurring now is not enough to account for all the heat presently coming out of Enceladus. One way out of this dilemma is to assume that some of the heat observed today was generated and stored internally in the past... (N)ow that the orbit's eccentricity has lessened, the heat emanating from the interior is a combination of heat produced today and in the past."