Rogue planets and brown dwarfs discussion

[Rakaydos]

I found an article talking about how Sol (probably) used to have 5 gas giants beyond the asteroid belt, but it was ejected from the solar system as part of moving Uranus and Neptune as far out as they are. Models of exoplanet systems suggest that events like this are even more common- every hot superjupiter would have ejected one or more rocky planets that were closer to the sun than where it formed.

Imagining a rogue gas giant with tidally heated moons is particularly interesting- there's no reason there couldnt be an intersteller Europa floating around somewhere, life forming without a star.

[Roastduck]

I was actually literally just talking to my astronomy professor about this. Her master's thesis involved going through the data gathered looking for Nemesis, and the data was inconclusive/didn't support it

[Rakaydos]

Did the thesis explain Uranus and Neptune forming so far out, this "early" in the solar system? I took that as one of the "proofs" for the rogue planet theory.

Or is nemisis something else?

[CalculusWarrior]

Nemesis is supposedly a brown dwarf or other massive body on a very elliptical orbit which apparently passes through the solar system every so often and causes havoc. There's no evidence to support this, though.

[Motokid600]

Rogue planets intrigue the help out of me. What would happen to Jupiter if it was cast out? Would it freeze down to a solid surface? Trying to imagine what these planets look like. And what are the chances of one paying SoL a visit?

[Vanamonde]

Although it is not large enough to initiate fusion, Jupiter has a great deal of heat left over from its formation. The matter which formed Jupiter, falling together under mutual gravitation, was heated by friction and collisions, and the planet has not had anywhere near enough time to radiate all that heat away. The result is that it actually gives off more heat that in receives from the sun. And that means that no, Jupiter would not freeze for a long time, even if had already been ejected from the solar system.

[Rakaydos]

Rogue planets intrigue the help out of me. What would happen to Jupiter if it was cast out? Would it freeze down to a solid surface? Trying to imagine what these planets look like. And what are the chances of one paying SoL a visit?

Space is big. one could miss us by a 12th of a lightyear and we'd never notice. Especially if it was an iceball.

As I mentioned, though, the idea of an ejected gas giant with tidally heated moons is interesting. No star, but the potential for life...