(4:16) viewed from many lightyears away they look the same, but a chthonian planet would probably have much less craters and mountains. The liquid hydrogen and pressure would slowly polish the core into an almost mountainless ball. its gas would also protect the core if there was an age of heavy bombardment in a system, making a chthonian planet look like a big orb in space.
You continue to delight and enlighten me. Loving it! I didn't think that gas planets could get below 5x Earth. I may have to update my "knowledge base" again.
Frequent updates are recommended :) Ye, dividing line between rocky and gaseous planets is roughly 2 earth radii. Mass is a bit weirder, can be anywhere from 1-20 earth masses.
I've always wondered if you could have a stray super jupiter flying through extrasolar space somewhere with a system of moons but no significant starlight, and if an ice moon there could sustain liquid oceans and life from the heat generated by tidal forces.
Maybe its a reason why The core of Mercury is 30% of its volume Maybe its a gas gaint before then migrated in and all of its gas got lost due to stellar winds Or does it not make sense?
Long ago, but who cares. This is seems unlikely for several reasons. - past-Mercury (with a Jupiter/Neptune-mass nonetheless) with it's high eccentricity would have caused havoc in the inner solar system, ejecting plants left and right. -The loss of atmosphere would be asymptotic in it's behaviour, starting of with a high loss rate, then petering out towards the end. Right now, Mercury has no atmosphere left to speak of. -The tail of lost gases would've intersected the other inner planets, adding more volatiles to them, possibly lots of ammonia and hydrocarbons. (Wouldn't we find traces of that somehow? Not sure though) -Mercury as a chthonian planet is tiny, at best the original object might've beena mini-Neptune (?) Many points of pain and uncertainties, but Mercury remains a mystery either way.
I am thinking of writing some browser based software that allows people to do this kind of world building interactively. I am thinking of making it 2 dimensional for simplicity, although I might add 3 dimensions later, before I get started I would like to hear anyone's thoughts from these videos, as they will be my primary inspiration for it. Also Idea's for names would be appreciated, as well as any other ideas for user interface or pretty much whatever you can think of.
Interest and informative video, especially on the term "dwarf gas giant" (oxymoron much ISU?). Never heard of it until now. GURPS may need to update their planet creation rules then to take into account as well as the notation about there being absolutely no chance of a habitable world existing within a star system that has a hot Jupiter (been a while since I took a deep look at those particular chapters), and said world being noticeably wetter compared to one whose wandering Jupiter's eccentricity is low enough for it to exist yet be comparatively drier. While we're on the subject at hand, I have the feeling that there's a particular tipping point to which a rocky planet larger than earth becomes a dwarf gas giant. Though I have a feeling that distance and temperature would have a factor in that. Still, an interesting question to consider. Not only that, but recalling your previous video on gas giants, it also made me wonder if there's a kind of "transitional" planet between liquid gas giants and ice gas giants. A kind of "slush" gas giant if you will. As for the Chthonian World potentially being a "dead" gas giant's core, first I've heard of that theory as well. It does raises the question of how one can tell through observation and spectral analysis if said rocky world is indeed a Chthonian planet or had always been a rocky world. I guess the age of said system and orbital eccentricity would help clear that inquiry a smidge. Also, before I forget, I assume that in a future video, there'll be a guide to what planets and/or celestial body types would most likely occupy those orbits we've calculated in those star system construction videos a while back? I would love to use those Lagrange notes for a few star system ideas that have been bouncing around in my head, though not really sure how they'll work on a Tatooine type star system. Math is probably way above my paygrade and all...
Sabersonic Regarding transitional planets - they will be discussed in future videos. Again I want to stress that Chthonian is very much a speculative term. Useful in science fiction but definitely not science fact.Finally yes, there will be a video covering how to place various different types of planets within the planetary system templates of previous videos.Thanks for watching. Stay tuned :)
There is a recent theroy that says Mercury might be the core of a hot Neptune that has migrated back out to where it is now. What do you think about this theory?
This makes me wonder if mercury is actually the core of a former gas giant that left behind the watery world that is our Earth, like what some theories state.
Being tidally locked to the sun and having an atmosphere means the temperature distribution is mostly even anyway and tgat massive storms would constantly be raging on those planets.
So, i have this idea, but I dont know if its possible, I have the idea of a Chthonian planet that totally lost its gaseous composition, leaving its core behind, so the thing is I imagine the gases that were left on its orbit still linger there, while the planet still follows its orbit, from the habitable world perspective I want this planet to play a Venus-Morning Star Role, being visible to the naked eye for some time during dawn before the sun rises up, but with the addition of the gases being perceived as a nebula of bright, scintillating rose and pinkish hues, and also visible during sunrise, imagine Earth dawn with its normal colors, also the apparition of its "Morning Star", but with a bright nubula-like aurora that can be seen during only that period of time, for this both the gas trail and planet must have a very high Albedo, the planet I think should be higher so it can be distinguished from the fake gas aurora. Also I dont know much about gases, so if there are gases that can reflect that much light and have the colors required to generate this effect?, can they also be found in gas or ice giants?, also would they remain along the orbit of the planet or they would disperse? Mostly I like the idea the moment I heard the word chthonic because I'm a huge mythology nerd and the word carries some cool stuff behind in what concerns mythology, also because I think it would be awesome the variety of myths and legends that would come up arround the dawnstar and the bright rose "nebula".
Could a hot jupiter have a toroidal wind pattern? Air rises on the hot side, blows to the cool side where it sinks, and then blows over to the hot side again, but deeper down in the planet. Then, it rises again.
I wonder if the retrograde rotation is what causes the deceleration necessary to suck the gas giant into such a close orbit? Whereas prograde would not sap as much momentum? Have we found the reasoning behind this?
I could see that the core of a gas giant having existed under that gas envelope for billions of years would have some unique formations do to that environment, I don't know what those would be or that they could be detected at astronomical distances but it's and interesting concept to me.
So where exactly is the line between gas dwarfs and super-earths? Your description of gas dwarfs, with a definite ocean under a heavy atmosphere, doesn't sound like a giant planet at all, where divisions between gas and liquid become more or less meaningless in a giant ball of ever strengthening pressure. That seems more like a description of the low end of the giant/sub-giant divide, but having said that I don't know what other middle ground the internal structure goes through between "basically just a really thick atmosphere" and "basically a failed brown dwarf." Although I will say I was under the impression that super-earths were between ~2 and ~10 Earth masses, which doesn't leave much room for a separate class between that and Neptune, so maybe the two are one in the same and I just got confused somewhere. :/
A gas dwarf is a super earth with a bigger atmosphere than most rocky planets and would be small like uranus and neptune with the rocky core the rest of the make up and the crushing atmosphere so they really can be either
For some reason I read the title as "extrastellar gas giants". Was kinda surprised why you never touched upon them :D Anyway, Artiflexian, you may remember one reddit comment (by u/Sithril) I made some month or two ago. Are you gonna look at how to create a star map?
I do remember that comment and star charts is on my to do list! Don't have much experience with star charts but its definitely an episode worth making. Stay tuned... :)
So, since chthonian planets would be hard to tell apart from regular rocky planets, and since hot jupiters appear to be incredibly common, I've always wondered - might Mercury, with its anomalous density, be such a chthonian planet? I know the prevailing wisdom is that Mercury lost its mantle in a massive impact event, but couldn't it just as well be the remnants of our own solar system's Hot Jupiter?
+420 Eat It There's not much agreement on exactly what makes a Hot Jupiter - some sources say anything less than 1 AU, others push in tighter. The closest I can find to a consensus is an orbit between 0.015 AU and 0.5 AU, and Mercury's orbit is 0.46 AU at aphelion, definitely inside that range.
Can a moon of a gas giant that is in the habitable zone be habitable? Since the gas planet is orbiting the parent star eclipses would be now and then common depending on the distance.
Possibly... We believe that Titan and Europa may be habitable, but the large amounts of radiation reflected at these moons buy their host planets is much too high for anything we can think of to survive. That being said I'm not entirely sure if Saturn likes to bake its moons like Jupiter does, so maybe Titan has a chance yet.
I generally have no problem following fast videos, but this is too much. Too much information/data too quickly. I would suggest toning the speed down for future videos.
Is is possible for the moon of a gas giant to be habitable? I assume for the moon to be habitable the planet itself would need to be located in the habitable zone, thus making it a hot jupiter. However, if hot jupiters tend to lack moons, and systems with hot jupiters tend to lack habitable worlds, just how plausible is this scenario?
It's very plausible. Hot jupiter's may lack moons but its not impossible for a hot jupiter to have moons, its just improbable. Also, computer models have shown that hot jupiter can have habitable worlds in their system. So that's also totally legit, in so far a creating a fictional setting is concerned.
@@enkiimuto1041 When captured they should become locked to the planet and not the sun anymore, I think. Objects are tidally locked to what they are orbiting.
Gas giants are giant and also gassy but would neptune be a gas giant or Uranus jupiter and saturn are my favorite gas giants . You know what could jupiter's great red spot be ragging over 200'000 years
+Eric Southard Degree is used to measure how far a value varies from an arbitrary reference point, whereas the Kelvin scale is designed to measure how far a value varies from an absolute reference point (zero energy). Thus in 1968, it was decided that "degree Kelvin" was in appropriate, and the scale should be stated as just "Kelvins".
The theory of system formation has the planets coalescing out of a protoplanatery disc. That would result in all planets orbiting in the same direction so there must be a mechanism, or even several mechanisms, that gives rise to retrograde orbits. Find the mechanism and it will be amenable to statistical analysis; ultimately the proportion of observed retrograde orbits is going to be an artefact of some external element; that might be the mechanism(s) involved but it might be something as distant as our methods of observation. Whatever the reasons the chances of the distribution being 50:50 only through random chance seem very low indeed. :)
Gas...dwarfs. WOW, had no idea those even existed! Appropos of...exoplanets in general, am I the only one bugged by how they "name" these new planets? Why the hell is the FIRST planet called (whatever) B? The first one should be A! That is just so...annoying. WHAT the...? Is there an actual reason? Seriously, wtf.