Why doesn't Tylo have an atmosphere?

[geb]

Tylo seems to be the kerbal equivalent of Ganymede. The real Ganymede has a very, very thin atmosphere, but it's pretty close to vacuum.

http://en.wikipedia.org/wiki/Ganymede_%28moon%29

Tylo might have been made larger to turn it into a challenging world, but it's keeping the Ganymede theme.

[djnattyd]

Siphoned off by gas-mining Vogons.

I've got my towel at the ready, there will be no panicking

[Xavven]

My guess is that Tylo's atmosphere was stripped away by solar wind, either directly, or as a result of Jool channeling its magnetosphere right into Tylo's orbit. A planet has to have a strong enough magnetic field to divert all that plasma away. http://en.wikipedia.org/wiki/Solar_wind#Atmospheres Perhaps Tylo does not have the internal makeup to create a strong magnetic field -- perhaps its core is too cold, or doesn't have enough electrically conducting fluid in it (lack of iron?) http://en.wikipedia.org/wiki/Dynamo_theory Or, perhaps its orbit places it in just the right spot for the radiation belt of Jool to bath it in concentrated plasma, much like Io's matter gets stripped away and added to Jupiter's magnetosphere: http://en.wikipedia.org/wiki/Magnetosphere_of_Jupiter#Role_of_Io

Edit: Another thought... since Tylo is tidally locked to Jool, do you think that perhaps its Coriolis effect is too small to create the necessary spiraling convective currents in the mantle, thus weakening its magnetic field?

Edited August 8, 2014 by Xavven

[Bomoo]

I'm thinking because the Jool system is still in development, and whatever exotic thing they had planned for Tylo's atmosphere is waiting on implementation.

[SlyReaper]

Venus is the same size as Earth. But compared to Venus, our atmosphere might as well be hard vacuum. Size and mass are not the only determining factors in what kind of atmosphere a planet or moon ends up with.

[Discovery173]

An idea that came to my mind regarding this issue (always considering that we are talking about a game) is that Laythe is still experiencing volcanic activity due to the constant gravitational strain it suffers from Jool and the other moons. Also, being so close to Jool, the planet's magnetosphere prevents the solar (Kerbolar?) wind from taking away the gases constantly emitted by the volcanoes in the surface. Tylo, on the other hand, has cooled down a long time ago, and lost its atmosphere over the years without protection from Jool's magnetosphere and its own lack of a magnetosphere, caused by its low rotational speed.

[regex]

Another thought... since Tylo is tidally locked to Jool, do you think that perhaps its Coriolis effect is too small to create the necessary spiraling convective currents in the mantle, thus weakening its magnetic field?

That would preclude Laythe from having an atmosphere as well so, no.

[RenevB]

At first I thought I was looking at this topic, except moved. It has some good points, but I would like to add one. I think that the question should actually be "Why does Laythe have an atmosphere?". In the real solar system, very little moons have atmospheres, and none of the Jovian moons, although a lot of them seem to have exospheres. I think the only moon with an actual atmosphere is Titan. (This brings me to an aside that Laythe may actually be the equivalent of Titan in KSP.) So moons without atmospheres seem to be the norm and moons with atmospheres the exception.

[kahlzun]

Tylo's gravity is about 3/4 Kerbins gravity.

Perhaps it is too cold to form an atmosphere? Laythe would be exposed to more tidal forces, perhaps Tylos simply froze out?

[SkyRex94]

Atmosphere's not only depend on mass. Only because a body is heavy enough to have one doesn't mean it has one becaue there are other factors too.

Look at our Solar System :

Ganymede has no atmosphere (or maybe just a very thin one like the moon)

BUT Titan has a denser atmosphere than our Earth although it is smaller and lighter than ganymede!!!

It also depends on varoius other things. Which elements are available on that body to form an atmosphere, at which tempereature they are in gas form, how high is the actual temperature on that body and so on

In short: there are bodies which are to small to have an atmosphere yes, and there are ones that are so heavy they certsainly have one. BUT there is a range between these sizes were a body can but don't need to have an atmosphere.

(The scale-downsize in mind) KSP's atmospheres and the bodies that haven't one are totally realistic (or plausible).

[jfull]

This discussion is reminding me of just how boring Tylo is...

I think it needs a bit of a makeover... perhaps some more varied terrain

[Pecan]

Tylo's even less dense?

According to the wiki they are the same size but Tylo is less dense, yes.

[treejoe4]

Since when do all rocks of the same size automaticly have the same atmosphere?

Because their gravity maintains an atmosphere that naturally collects when the planet forms

[SkyRender]

Probably Tylo has no magnetosphere (or a very weak one, or a neutralized one due to magnetic interference from neighboring bodies cancelling it out). For whatever reason, having a magnetosphere seems to be a key component to having a persistent atmosphere. More to the point, just because we've only ever observed large rocky bodies having atmospheres in our solar system does not indicate that all large rocky bodies absolutely must have an atmosphere. Our sample size is extremely limited and confined to our solar system on top of that.

[jfull]

Because their gravity maintains an atmosphere that naturally collects when the planet forms

But that is dependant on multiple factors, including the planet's composition, and whether it has a magnetic field to shield its atmosphere from solar wind.

[SkyRender]

But that is dependant on multiple factors, including the planet's composition, and whether it has a magnetic field to shield its atmosphere from solar wind.

Also significant is if there's any way for the gaseous elements to take a gaseous form. To wit: Titan is not much denser than the moon, yet has a very thick atmosphere. The moon has large quantities of elements that have naturally-occurring gaseous states (most notably its abundance of oxygen). Both have meaningful magnetospheric influence as well (in Titan's case, it's being shielded by Saturn's magnetosphere; in the moon's case, it has both the Earth's magnetosphere and its own). However, the moon is effectively inert since it lacks any form of transition process to separate those potentially-gaseous elements from their non-gaseous bindings (the most-commonly-observed method for that happening being vulcanism).

[cantab]

For whatever reason, having a magnetosphere seems to be a key component to having a persistent atmosphere.

Venus says hello.

There doesn't seem to be one factor determining whether or not a body has atmosphere.

[SkyRender]

Venus says hello.

There doesn't seem to be one factor determining whether or not a body has atmosphere.

Well, there is one definite factor that's hard to argue: there has to be a sufficient quantity of elements that can take a gaseous form. I mean really, that's kind of a no-brainer, but still.

[Wallace]

I've got my towel at the ready, there will be no panicking

No panicking? Well that may not last if the Vogons start to read their poetry...

[cantab]

Well even that's situational, and you have to consider compounds as well as elements. (I don't know any compounds with lower boiling points than any of their constituent elements, but maybe some exist). If it's hot enough rock vapour can form an atmosphere, if it's cold enough nitrogen and oxygen will be solid.

[tychochallenge]

I think tylo needs some 'form' of an atmosphere, not completely an exosphere; in comparison duna has about 20% kerbin's atmosphere asl, tylo can have something like 3-5% so its an atmosphere, but parachutes will not work: sorta like tylo in altering kerbol, except with a thinner atmosphere. Maybe Tylo once had a thick atmosphere, but another moon of jool crashed into it early on stripping away most of its former atmosphere.

[TrooperCooper]

The reason is simple...

THEY have been visiting Tylo...

[spaceman1999]

Magathreans got bored and didn't give it an atmosphere.

[SpaceSphereOfDeath]

I say let's give tylo the old Moho atmosphere, but even thinner and 42 times as deadly!

[cantab]

Was that the one that was so hot it'd overheat your engines when they weren't even running? They should rework Eve to be like that >:-D