In other news, Universe Sandbox appears to confirm that a Hot Jupiter setup isn't at all implausible. I constructed a gas giant with 1.25 Jupiter's mass and sent it around the sun at 1.05 AU. Around the gas giant I sent an Earth-like moon with a 10,000 km radius, which had a Charon-sized moon of its own, and, further out, a second gas giant (about half the size of Neptune) orbiting the bigger one. All orbits were stable.
(It MAY be a bitch for spacecraft, depending- Charon orbited the Earth every four and a half hours. You could probably get some hella nice gravity slingshots, though?)
Also, I have no idea how Universe Sandbox calculates temperature for moons. Hot Jupiter is about -10 degrees Celsius; Neptune-moon is about 55 degrees.
(It MAY be a bitch for spacecraft, depending- Charon orbited the Earth every four and a half hours. You could probably get some hella nice gravity slingshots, though?)
Also, I have no idea how Universe Sandbox calculates temperature for moons. Hot Jupiter is about -10 degrees Celsius; Neptune-moon is about 55 degrees.
So Universe Sandbox has confirmed, as far as I'm going to investigate it, that a hot-Jupiter scenario for my conworld is plausible. The star is about 5% more luminous than the Sun is, and the planet- a gas giant with 1.25 the mass of Jupiter- is at 1.10 AU. As for the "moon", it's about 9000 km in radius and somewhat more massive than the Earth. It has no sub-moon. It's unclear whether you can ever make sub-moons stable.
In several ways, I feel like inhabited moons might be even more plausible than inhabited planets. (They can piggyback off their planets' magnetic fields for protection from the ravages of solar wind, and moons are more common than planets). There's only one issue, though, which is the seasons. If my moon orbits its planet once every five days or so, then its axial procession is relative to the planet, and has nothing to do with seasons. Instead, the planet is going to have a somewhat more eccentric orbit than Earth does, so that the distance from the sun changes enough to affect the climate; "winter" occurs at the aphelion and "summer" at the perihelion. As a corollary, the seasons are world-wide; there's no hemisphere swap, and no area is unscathed.
I suspect this will create several new climate types. For example, tropical lowlands will still have the moderating effects of being in the middle of the planet, so they won't experience really unpredictable heat waves or cold snaps, but they'll still have temperature changes as the year progresses. For example, maybe you'd have a "tropical rainforest" climate that ranges from the lower 70s (lower 20s C) in January to 90 (lower 30s C) in July- a more moderate version of the southern US or China. Other than that, though, I'm not sure what a planet-wide seasonal cycle would do.
(On the other hand, I'm not sure how much of Sandbox's climate simulation to believe. If you give Venus, for example, an Earth-like atmosphere instead of the one it has, add water and give it an Earth-like day, it freezes over.)
In several ways, I feel like inhabited moons might be even more plausible than inhabited planets. (They can piggyback off their planets' magnetic fields for protection from the ravages of solar wind, and moons are more common than planets). There's only one issue, though, which is the seasons. If my moon orbits its planet once every five days or so, then its axial procession is relative to the planet, and has nothing to do with seasons. Instead, the planet is going to have a somewhat more eccentric orbit than Earth does, so that the distance from the sun changes enough to affect the climate; "winter" occurs at the aphelion and "summer" at the perihelion. As a corollary, the seasons are world-wide; there's no hemisphere swap, and no area is unscathed.
I suspect this will create several new climate types. For example, tropical lowlands will still have the moderating effects of being in the middle of the planet, so they won't experience really unpredictable heat waves or cold snaps, but they'll still have temperature changes as the year progresses. For example, maybe you'd have a "tropical rainforest" climate that ranges from the lower 70s (lower 20s C) in January to 90 (lower 30s C) in July- a more moderate version of the southern US or China. Other than that, though, I'm not sure what a planet-wide seasonal cycle would do.
(On the other hand, I'm not sure how much of Sandbox's climate simulation to believe. If you give Venus, for example, an Earth-like atmosphere instead of the one it has, add water and give it an Earth-like day, it freezes over.)
I don't know enough of the physics to say for sure, but I'm not exactly surprised. Venus is smaller than Earth, thus it's going to have a lot less geothermal heating going on. I don't know if its orbit is close enough to counteract that. You might try adjusting its distance inward to see if you can thaw the iceball.
Also have you found any better way of building a solar system than editing Sol or starting from absolute scratch? The pregenerated solar systems I try keep going nova for some reason :/
Also have you found any better way of building a solar system than editing Sol or starting from absolute scratch? The pregenerated solar systems I try keep going nova for some reason :/
quoting Nessari, Illúbequía, Seattle, Cascadia:I don't know enough of the physics to say for sure, but I'm not exactly surprised. Venus is smaller than Earth, thus it's going to have a lot less geothermal heating going on. I don't know if its orbit is close enough to counteract that. You might try adjusting its distance inward to see if you can thaw the iceball.
Also have you found any better way of building a solar system than editing Sol or starting from absolute scratch? The pregenerated solar systems I try keep going nova for some reason :/
I've been starting from scratch, but have needed to do so several times- I can't make Sandbox open a lot of my simulations.
Yes, the going nova bit is obnoxious. Even just doubling the Sun's usual mass makes it go nova.
Also, no, even if you make Venus the mass of Earth, it still freezes over. Not so much, I don't think, that it couldn't warm up with some extra carbon dioxide- it's about -20 C on average. Adjusting its orbit inward does work- it's just below freezing at 0.6 AU. Also, it seems to be impossible to make a planet be at any distance you want- sometimes Sandbox likes to adjust it again for you, which is annoying.
quoting Nessari, Illúbequía, Seattle, Cascadia:Any feedback from it on why it does that? Could be gravitational reasons certain orbits aren't tenable.
I really need to work out all the details of Šaol's star, so I can edit Aldebaran into it.
Nope. You just try typing in, say, 0.7 AU for Venus's orbit, and it will decide 0.65 was a much better choice and give you that. It often tries to screw with the eccentricity, too.
If it’s just climate simulations you need, I’d suggest the Planetary Climate Sim over at the Observatory might be a better place to start. Much more detailed input and output, with none of the problems mentioned above — though it is mostly intended for Earthlike planets. For Venus it still underestimates the temperature at about 100C, presumably because the only clouds it takes into account are water clouds.
If you’re running a newer windows computer, you’d want the »Planetary Climate Sim for Win32« version linked at the very bottom of the page rather than the main version linked above it. It works on my computer from 2014, though I’ve no idea if any versions still work as far as non-Windows machines go.
