[opportunity]

20 years ago everyone thought the planets came from the stars and were slowly moving into the sun.....or either you are not that old to know that or too old to remember?

[Kryptid]

Its a thick carpet to dig under to find those citations.

Then I'll save some time: there is no evidence that the masses of the four outer planets has changed significantly in the past fifty years.

How did we find out, and when, that everything beyond Mars is a Gaseous planet other than bare rock core exo-planet stuff?

They would technically be mostly composed of supercritical fluids instead of gas. I'm not sure when these things were discovered, but I'm guessing the Voyager probes had a lot to do with it. One of the biggest clues to the internal structure of the outer planets would be their density. It's much too low for them to be mostly rock (although their cores could conceivably be rocky).

20 years ago everyone thought the planets came from the stars and were slowly moving into the sun.....or either you are not that old to know that or too old to remember?

What do you mean by "came from the stars"? You mean the proto-planetary disk? As far as I know, that model hasn't changed. I don't recall hearing that the planets are slowly moving into the Sun, though (unless you mean the Sun expanding into a red giant and consuming them).

[opportunity]

Well, yeah, right? Isn't that core to proto-planet theory, that this solar system came from outer-space rubble? You've never hear that idea before?

[Kryptid]

Well, yeah, right? Isn't that core to proto-planet theory, that this solar system came from outer-space rubble? You've never hear that idea before?

Sounds like the proto-planetary disk to me.

[opportunity]

Is that story book still around though?