Can a Ganymede-sized moon rotate around a planet with the mass like Uranus (14 to 15 T-masses)?

Question

I need this for the paper I'm writing...

- What about an earth-sized moon?

- How will the primary appear when viewed from the satellite?

- What kind of geological activity, seasons and weather patterns can we expect in such a hypothetical moon?

- How far does this system have to be from a G2 star to maintain liquid water? How about if the pair orbited a K1 star? Assuming tides are present, can liquid water exist in such a moon if the primary were at the fringes of the so-called "habitable zone?" (main world has an almost circular orbit while the moon has a slightly eliptical orbit)

Please feel free to share your insights and opinions. Thanks!

Answer 1

Why not? Our own Moon is almost as big as Ganymede, and orbits a planet much smaller than Uranus. Like our Moon, and like the Galilean satellites, its rotation will be tidally locked.

As the rest of your questions, no, I am not going to do your research for you. It's your homework, not mine.

Answer 2

Given that a Jupiter sized planet has been found orbiting a star at the same distance Earth is from the Sun, there is no reason to believe that a Uranus sized planet couldn't be in a similar orbit. That is necessary for liquid water to exist, and it's certainly possible for a massive planet to have one or two moon or even Ganymede sized satellites as the result of a collision during the planet's growth. The planet would of course dominate the sky. The moon however would lack the gravity to hold onto a dense atmosphere and the intense heat of the Sun would drive off the water, even if it is a K-type star. If the planet were farther way, the water would merely freeze and leave the moon as a twin of Europa, Ganymede or Callisto depending on the proportion of rock and metal to ice. They would have to have the mass of Mars at least to even have any sort of atmosphere, and a molten interior to create and maintain a magnetic field that would protect the atmosphere from attack on the part of the solar wind. Small bodies like the moon cool off and become geologically inert, shutting off the magnetic field and the cycles that create and maintain a planets atmosphere and hydrosphere if it has one.  There would of course be tides, with the moon forces to keep one side staring at the planet all the time and a day lasting the same number of days as it takes to circle the planet once. Perhaps you should consider the possibility that instead of the moon harboring life, the planet might be able to support some form of life because ice giants do have a lot of water, methane, ammonia and everything else needs to create the precurors of life.