Quote from: Nostromo on Sep 15, 2016, 10:30:47 AM
Nice to know you like Exoplanetology Engineer! I really didn't want to get into the brown dwarf discussiom so as to keep it from going overboard that's why I was just stopping at "it will collapse". That's what's good about Astronomy you can write a whole book on just one topic...
It makes sense that so many hot jupiters have been discovered since they orbit their host star quicker...that's how they detect planets, they see a Star's total emitted light drop by a tiny fraction of a percentage point once the planet crosses it. There are other method too though...
Anyhow more Gas Giants like Jupiter and Calpamos will be discovered in the future as these have huge orbits of 20-200+ years or more...so have to be patient.
Engineer, you think they're might be a formed gas giant 3-7x bigger than Jupiter out there? 10x is really pushing it for a formed Gas Giant. I like that saying "formed" to differentiate them from hot jupiters or semi brown dwarves, etc..
It's also amazing when you think about the size of stars..can you imagine the ones that are 1500x bigger than our Sun...insane...whole other subject though.
Yea honestly, brown dwarfs are my favorite. They're so bizarre!
I think it's fair to say a large size gas giant might exist, but it's density would be low, a lot like saturn's, otherwise it would shift into brown dwarf territory. Ultimately, I'd say it's too early to tell, and we'll have to wait and see what other interesting planets get discovered in the years to come. Also, we've all be talking about calpamos as if it were a gas giant; it looks like a gas giant, but it could be an ice giant which might have different factors at work that impact it's size/density. It's all fun to think about and rationalize, but ultimately I think the movies just don't give us enough information to say difinitively what calpamos really is.
The same is true for moons, for that matter. We have yet to discover exomoons, but the moons in our own solar system are all so unique from one another. There's no telling what's possible there!
When it comes to rocky planets and moons though, I did read a really interesting paper about the size of the planet/moon and it's habitability. If the planet is too small, the molten core will eventually cool and solidify effectively shutting off the magnetosphere. Without the magnetosphere solar winds would whisk away any atmosphere which is what happened/is happening to Mars. Earth is just the right size, our gravity is strong enough to generate heat from friction at our core keeping it molten, and allowing the magnetosphere to stay on. Go any larger, like 'super-earths,' the magnetosphere also stays on but geological activity and volcanism become too promenant and would likely result in a toxic atmosphere or a run away greenhouse gas effect. That's all theoretical though; we can't see the super-earths well enough to tell if that's true or not.
But that raises an interesting question about lv-426 though! Whether you believe it's 1,200 km or 12,000 km, it's too small to sustain a magnetosphere, so how does it retain its atmosphere well enough to make terraforming a worthwhile venture? I have a rationalization for that: calpamos generates a strong magnetsphere a lot like Jupiter does, and lv-426 must orbit close enough to get some protection from calpamos's magnetosphere. That's one of my fan-theories though, I dunno if anyone else thinks that way about too or not. Lol
