Hi there! I'm new here Please Register or Log in to view the hidden image! , and I was looking for some information, if people here can provide me with that? I'm working on a Worldbuilding project, where I'm creating a fictional universe, but I want the worlds that I and others would create, to be based on real scientific facts, with real astronomical data, and to be subject to our natural laws of physics, just like other worlds in our real universe. I need a planet that has a deep and thick atmosphere and that's 3 times the size of Jupiter. The atmosphere equals 2 thirds of the planet though. I need it to be that way because one of the many species on that planet live in the atmosphere, the rest being on the surface. Would the mass of this planet create extreme gravity in such a way that most of the life forms there are gigantic? This planet that I'm talking about, is in the 4th orbit around it's F5 main sequence star, and actually making it the last one in the orbital order. How distant should this planet be in order for this liquid water to be maintained, and not freeze over? Could 2.3 A.U. be ok? I need facts behind this. Since this is the forum for astronomy, and exobiology I thought I ask my question here Please Register or Log in to view the hidden image! Any answers that remotely satisfy the information I need for these questions would be very appreciated. I also hope that this might also turn into an interesting discussion among those who are heavily into astronomy and astrophysics. Thank you Please Register or Log in to view the hidden image!. PS: Also, whoever feels like she/he can contribute to this Worldbuilding project in any way possible, or wants to be a part of it, please let me know. I take all kinds of people, with all kids of ideas and all kinds of advices/help they offer, well ... 99.99% of the time hehe :mrgreen:. As long as the project is still what the name suggests and does not turn into something else.